Johann Rafelski

Interests

Research

Theoretical subatomic, astroparticle, plasma physics, nuclear fusion, cosmology

Teaching

Relativity, Quantum, Particle, Nuclear

Courses

Scholarly Contributions

Books

• Rafelski, J. (2022). Modern Special Relativity. https://doi.org/10.1007/978-3-030-54352-5: Springer-Nature. doi:https://link.springer.com/book/10.1007/978-3-030-54352-5
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  Designed for students, it provides many solved problems that help master the subjectThe concepts of special relativity are introduced in a clear and simple way, without making use of four-vector formalismPresents the existing connections between special relativity and particle, nuclear, and high intensity pulsed laser physicsGives a detailed historical overview of developments in special relativity before and after 1905
• Rafelski, J. (2019). Spezielle Relativitätstheorie heute. Springer-Spectrum. doi:10.1007/978-3-662-59420-9
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  German translation by Author of the English undergraduate text in press 2020 "Modern Special Relativity", German abstract : Dieses Lehrbuch bietet eine in der Form neue und einmalige Darstellung der speziellen Relativitätstheorie, in der präzise und nachvollziehbar die Grundlagen entwickelt und dabei zahlreiche gängige Missverständnisse zu vermeintlichen Folgerungen aus der Theorie ausgeräumt werden. Hier wird die Relativitätstheorie so präsentiert, dass nichts paradox oder unklar bleibt.Neben der sorgfältigen, elementaren Einführung mit zahlreichen Übungen, vorgerechneten Beispielen und vielen Diskussionen zu konzeptionellen Fragen knüpft dieser Band auch an aktuelle Forschungsthemen an, so dass die Leser die spezielle Relativitätstheorie von den Grundlagen bis zu ihren Grenzen erkunden können. Auf die Verwendung des Tensorkalküls und von Vierervektoren verzichtet das Buch, um damit verbundene zusätzliche Schwierigkeiten zu vermeiden. Das Werk präsentiert somit die spezielle Relativitätstheorie so, dass die Einstiegskapitel von Erstsemestern verwendet werden können. Dank zunehmender Vertiefung der Themen in den nachfolgenden Kapiteln bleibt es für Physikstudierende bis zum Bachelor ein wertvoller Begleiter.
• Rafelski, J. (2017). Relativity Matters. Springer. doi:10.1007/978-3-319-51231-0
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  Rafelski presents Special Relativity in a language deemed accessible to students without any topical preparation - avoiding the burden of geometry, tensor calculus, and space-time symmetries – and yet advancing in highly contemporary context all the way to research frontiers. Special Relativity is presented such that nothing remains a paradox or just apparent, but rather is explained.A text of similar character, content, and scope, has not been available before. This textbook describes Special Relativity when rigid material bodies are introduced describing the reality of body contraction; it shows the relevance of acceleration and the necessary evolution of the theoretical framework when acceleration is critical. This book also presents the evolving views of Einstein about the aether.In addition to a careful and elementary introduction to relativity complete with exercises, worked examples and many discussions, this volume connects to current research topics so that readers can explore Special Relativity from the foundation to the frontier.
• Rafelski, J. (2016). Melting Hadrons, Boiling Quarks - From Hagedorn Temperature to Ultra-Relativistic Heavy-Ion Collisions at CERN. Springer. doi:10.1007/978-3-319-17545-4
• Kapusta, J., Muller, B., & Rafelski, J. (2003). Quark-Gluon Plasma: Theoretical Foundations. Elsevier.
• Letessier, J., & Rafelski, J. (2002). Hadrons and quark - gluon plasma. Cambridge University Press.

Chapters

• Rafelski, J. (2020). Die Erste Stunde (The first hour). In FIAS Interdisciplinary Science Series: Discoveries at the Frontiers of Science(pp 331-349). Springer-Nature. doi:https://doi.org/10.1007/978-3-030-34234-0_22
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  I recall my "first hour" events following on my meeting in Fall 1968 in theclassroom with my academic teacher and thesis mentor Prof. Dr. Dr. h.c.multiple Walter Greiner. My comments focus on the creation of the new "strongfields" domain of physics in Frankfurt. I argue that this was the researchfield closest to Walter's heart during his lustrous academic career. I willdescribe the events that lead on to Greiner's course books, Walters actionsleading to the rise of Frankfurt School of Theoretical Physics, and show how astability principle defined his science.[Journal_ref: FIAS Interdisciplinary Science Series in press: Discoveries at the Frontiers of Science: From Nuclear Astrophysics to Relativistic Heavy Ion Collisions by Johannes Kirsch (Editor), Stefan Schramm (Editor), Jan Steinheimer-Froschauer (Editor), Horst Stöcker (Editor) ] http://arxiv.org/abs/1804.09909v1
• Rafelski, J., Kirsch, J., Muller, B., Reinhardt, J., & Greiner, W. (2017). Probing QED Vacuum with Heavy Ions. In FIAS Interdisc. Sci. Ser.: New Horizons in Fundamental Physics,(pp 211-251). doi:https://doi.org/10.1007/978-3-319-44165-8_17
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  We recall how nearly half a century ago the proposal was made to explore the structure of the quantum vacuum using slow heavy-ion collisions. Pursuing this topic we review the foundational concept of spontaneous vacuum decay accompanied by observable positron emission in heavy-ion collisions and describe the related theoretical developments in strong fields QED.
• Rafelski, J. (2016). About ‘Distinguishable Particles’. In Melting Hadrons, Boiling Quarks - From Hagedorn Temperature to Ultra-Relativistic Heavy-Ion Collisions at CERN: With a Tribute to Rolf Hagedorn(pp 179-182).
• Rafelski, J. (2016). Hot Quark Plasma in ISR Nuclear Collisions: January 1981. In Melting Hadrons, Boiling Quarks - From Hagedorn Temperature to Ultra-Relativistic Heavy-Ion Collisions at CERN: With a Tribute to Rolf Hagedorn(pp 375-378).
• Rafelski, J. (2016). Melting Hadrons, Boiling Quarks. In Melting Hadrons, Boiling Quarks - From Hagedorn Temperature to Ultra-Relativistic Heavy-Ion Collisions at CERN: With a Tribute to Rolf Hagedorn(pp 417-439).
• Rafelski, J. (2016). On the Hadronic Mass Spectrum: 2014. In Melting Hadrons, Boiling Quarks - From Hagedorn Temperature to Ultra-Relativistic Heavy-Ion Collisions at CERN: With a Tribute to Rolf Hagedorn(pp 229-234).
• Rafelski, J. (2016). Possible Experiments with Heavy Ions at the PS/SPS: CERN SPC 1982. In Melting Hadrons, Boiling Quarks - From Hagedorn Temperature to Ultra-Relativistic Heavy-Ion Collisions at CERN: With a Tribute to Rolf Hagedorn(pp 379-386).
• Rafelski, J. (2016). Spotlight on Rolf Hagedorn. In Melting Hadrons, Boiling Quarks - From Hagedorn Temperature to Ultra-Relativistic Heavy-Ion Collisions at CERN: With a Tribute to Rolf Hagedorn(pp 3-20).
• Rafelski, J. (2016). What Happened to ‘Strangeness in Quark-Gluon Plasma: 1982’. In Melting Hadrons, Boiling Quarks - From Hagedorn Temperature to Ultra-Relativistic Heavy-Ion Collisions at CERN: With a Tribute to Rolf Hagedorn(pp 387-388).
• Labun, L., & Rafelski, J. (2013). Temperature of Electron Fluctuations in an Accelerated Vacuum. In Towards Ultimate Understanding of the Universe(pp 153-158). World Scientific.
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  Editor: Chen, P
• Rafelski, J., & Labun, L. (2013). Critical Acceleration and Quantum Vacuum. In Towards Ultimate Understanding of the Universe(pp 141-152). World Scientific.
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  Editor: Chen, P
• Rafelski, J. (1998). Relativistic Quark Physics. In Relativistic Quark Physics: 5th International Conference on Relativistic Aspects of Nuclear Physics 27-29 Aug 1997. Rio de Janeiro, Brazil:(pp 288-338). doi:https://doi.org/10.1142/9789814528917_0016
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  We present a brief survey of the development of nuclear physics towardsrelativistic quark physics. This is followed by a thorough discussion of thequest for the observation of the dissolution of nuclear matter into thedeconfined quark matter (QGP) in relativistic nuclear collisions. Use ofstrange particle signatures in search for QGP is emphasized.
• Greiner, W., Muller, B., & Rafelski, J. (1985). Evolution of the Vacuum State in Supercritical Potentials. In Quantum Electrodynamics of Strong Fields(pp 257-300). Berlin, Heidelberg: Springer, Berlin, Heidelberg. doi:10.1007/978-3-642-82272-8_10
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  Three types of experiments probing a supercritical external field can be imagined, in principle. First, experiments where a subcritical but strong field is made supercritical for a certain finite period of time; then those in which a subcritical external field is rendered supercritical and made to remain so forever; and, finally, experiments that are carried out completely in a supercritical field. The prototype of the first kind of experiments — and the only one presently feasible — is the sub-Coulomb barrier collision of very heavy ions, such as uranium on uranium, Chapts. 12, 13. The second type of experiment corresponds, for instance, to the creation of a stable supercritical nucleus, initially stripped of electrons, by a nuclear fusion process. A typical experiment of the third kind is the ionization of a (hypothetical) supercritical atom and the observation of the resulting spontaneous pair creation (γ absorption accompanied by positron line emission).
• Greiner, W., Muller, B., & Rafelski, J. (1985). Experimental Test of Supercritical Fields in Heavy-Ion Collisions. In Quantum Electrodynamics of Strong Fields(pp 345-388). Berlin, Heidelberg: Springer, Berlin, Heidelberg. doi:10.1007/978-3-642-82272-8_13
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  This chapter describes the highlights of experimental research undertaken in recent years to get information on the physics of superheavy quasimolecules and, ultimately, to detect the decay of the neutral vacuum. Measurements of x-ray radiation, inner-shell hole production and electron emission have established the formation of superheavy quasimolecules and demonstrated the special properties of relativistic electron states in strong Coulomb potentials. To set the stage for a description of the latest development we introduce the experimental detectors used to measure positron spectra and subsequently discuss conversion processes producing background positrons and methods to deal with them. Results from experiments designed to study the gross features of positron emission are found to be in excellent agreement with theoretical predictions. In addition, however, several independent experiments have discovered remarkable narrow line structures in the emission spectrum. Further evidence indicates that the source of emission moves with the center of mass velocity and does not coincide with the individual nuclei. This supports the following interpretation: The lines are due to spontaneous positron emission in a supercritical potential. Their narrow width is due to the formation of longlived (≳10−19 s) “giant” nuclear compound systems of charge Z ~ 182...190. Successes and remaining problems of this interpretation will be discussed in detail. At the close of this chapter attempts will be described to construct a reaction model, based on the idea of capture in a pocket of the internuclear potential, which gives a coherent explanation of giant nucleus formation and spontaneous positron formation.

Journals/Publications

• Rafelski, J. (2024). Homage to Harald Fritzsch. International Journal of Modern Physics A, 39(09n10), 2441018. doi:10.1142/S0217751X24410185
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  Homage to Harald Fritzsch, a distinguished scientist, coinventor of QCD
• Evans, S., & Rafelski, J. (2023). Improving Euler-Heisenberg-Schwinger Effective Action with Dressed Photons. Acta Physica Polonica A, 143(6), S1-S200. doi:10.12693/APhysPolA.143.S13
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  We implement a longstanding proposal by Weisskopf to apply virtual polarization corrections to the in/out external fields in the study of the Euler-Heisenberg-Schwinger effective action. Our approach requires distinguishing the electromagnetic and polarization fields based on mathematical tools developed by Białynicki-Birula, originally for the Born-Infeld action. Our solution is expressed as a differential equation where the one-loop effective action serves as input. As a first result of our approach, we recover the higher order one-cut reducible loop diagrams discovered by Gies and Karbstein.
• Grayson, C., Yang, C., Formanek, M., & Rafelski, J. (2023). Electron–positron plasma in BBN: Damped-dynamic screening. Annals of Physics, 458, 169453. doi:10.1016/j.aop.2023.169453
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  We characterize in detail the dense e−e+γ plasma present during the Big-Bang Nucleosynthesis (BBN) and explore how it is perturbed electromagnetically by “impurities, i.e., spatially dispersed protons and light nuclei undergoing thermal motion. The internuclear electromagnetic screened potential is obtained (analytically) using the linear response approach, allowing for the dynamic motion of the electromagnetic field sources and the damping effects due to plasma component scattering. We discuss the limits of the linear response method and suggest additional work needed to improve BBN reaction rates in the primordial Universe. Our theoretical methods describing the potential between charged dust particles align with previous studies on planetary and space dusty plasma and could have a significant impact on the interpretation of standard cosmological model results.
• LaForge, E., Price, W., & Rafelski, J. (2023). Superheavy elements and ultradense matter. The European Physical Journal Plus, 138(9), 812. doi:10.1140/epjp/s13360-023-04454-8
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  In order to characterize the mass density of superheavy elements, we solve numerically the relativistic Thomas–Fermi model of an atom. To obtain a range of mass densities for superheavy matter, this model is supplemented with an estimation of the number of electrons shared between individual atoms. Based on our computation, we expect that elements in the island of nuclear stability around Z= 164 will populate a mass density range of 36.0–68.4 g/cm 3 . We then extend our method to the study of macroscopic alpha particle nuclear matter condensate drops.
• Price, W., Formanek, M., & Rafelski, J. (2023). Born-Infeld Nonlinear Electromagnetism in Relativistic Heavy Ion Collisions. Acta Physica Polonica A,, 143(6), S1-S200. doi:10.12693/APhysPolA.143.S87
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  We study the effect of the limiting field strength of Born-Infeld electromagnetism on the dynamics of charged particle scattering. We formulate the Born-Infeld limiting field in an invariant manner, showing that it is the electric field-dominated eigenvalue “a” of the field tensor Fµν which is limited rather than the individual field vectors. Heavy ion collisions in particular provide uniquely large values of the field invariants that appear in the Born-Infeld action, amplifying nonlinear effects. Thus “a” is the dominant input into the force between heavy ions that we use to compute the scattering angle as a function of the impact parameter. We evaluate the Born-Infeld effects, showing relevance at small impact parameters and exhibiting their dependence on the value of the limiting field strength.
• Rafelski, J., Birrell, J., Steinmetz, A., & Yang, C. T. (2023). A Short Survey of Matter-Antimatter Evolution in the Primordial Universe. Universe, 9(7), 309. doi:10.3390/universe9070309
• Rafelski, J., Evans, S., & Labun, L. (2023). Study of QED singular properties for variable gyromagnetic ratio g≃2. Physical Review D, 107(7), 076002. doi:10.1103/PhysRevD.107.076002
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  Using the external-field method, i.e., evaluating the effective action Veff for an arbitrarily strong constant and homogeneous field, we explore nonperturbative properties of QED allowing arbitrary gyromagnetic ratio g. We find a cusp at g=2 in (a) The QED b0-renormalization group coefficient, and in the infinite-wavelength limit in (b) a subclass containing the pseudoscalar P2n=(E→·B→)2n of light-light scattering coefficients. Properties of b0 imply for certain domains of g asymptotic freedom in an Abelian theory.
• Rafelski, J., Steinmetz, A., & Yang, C. (2023). Dynamic fermion flavor mixing through transition dipole moments. International Journal of Modern Physics A, 38(31), 2350163. doi:10.1142/S0217751X23501634
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  In this paper, we show that Majorana neutrino °avor mixing can be driven by transition dipole moments in the presence of external electromagnetic ¯elds. We demonstrate the sensitivity of the rotation mixing matrix to strong ¯elds obtaining dynamical mass eigenstates in the two- °avor model. The three-°avor case, and extensions to the quark sector, is introduced.
• Steinmetz, A., Yang, C., & Rafelski, J. (2023). Matter-antimatter origin of cosmic magnetism. Physical Review D, 108(12), 123522. doi:10.1103/PhysRevD.108.123522
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  We explore the hypothesis that the abundant presence of relativistic antimatter (positrons) in the primordial Universe is the source of the intergalactic magnetic fields we observe in the Universe today. We evaluate both Landau diamagnetic and magnetic dipole moment paramagnetic properties of the very dense primordial electron-positron e+e - plasma, and obtain in quantitative terms the relatively small magnitude of the e+e- magnetic moment polarization asymmetry required to produce a consistent self-magnetization in the Universe.
• Grayson, C., Formanek, M., Rafelski, J., & Müller, B. (2022). Dynamic magnetic response of the quark-gluon plasma to electromagnetic fields. Physical Review D, 106(1), 014011. doi:10.1103/PhysRevD.106.014011
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  We investigate the electromagnetic response of a viscous quark-gluon plasma in the framework of the relativistic Boltzmann equation with current conserving collision term. Our formalism incorporates dissipative effects at all orders in linear response to the electromagnetic field while accounting for the full space and time dependence of the perturbing fields. As an example, we consider the collision of two nuclei in a stationary, homogeneous quark-gluon plasma. We show that for large collision energies the induced magnetic fields are governed by the response of quark-gluon plasma along the light cone. In this limit, we derive an analytic expression for the magnetic field along the beam axis between the receding nuclei and show that its strength varies only weakly with collision energy for sNN≥30 GeV.
• Evans, S., & Rafelski, J. (2021). Particle production at a finite potential step: Transition from Euler-Heisenberg to Klein paradox. The European Physical Journal A, 57(12), 341. doi:https://doi.org/10.1140/epja/s10050-021-00654-x
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  Spontaneous pair production for spin-$1/2$ and spin-$0$ particles is exploredin a quantitative manner for a static $\tanh$-Sauter potential step (SS),evaluating the imaginary part of the effective action. We provide finite-valuedper unit-surface results, including the exact sharp-edge Klein paradox (KP)limit, which is the upper bound to pair production. At the vacuum instabilitythreshold the spin-$0$ particle production can surpass that for the spin-$1/2$rate. Presenting the effect of two opposite sign Sauter potential stepscreating a well we show that spin-$0$ pair production, contrary to the case ofspin-$1/2$, requires a smoothly sloped wall.[Journal_ref: ]
• Formanek, M., Grayson, C., Rafelski, J., & Müller, B. (2021). Current-Conserving Relativistic Linear Response for Collisional Plasmas. Annals of Physics, 434, 168605. doi:https://doi.org/10.1016/j.aop.2021.168605
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  We investigate the response of a relativistic plasma to electromagneticfields in the framework of the Boltzmann equation incorporating a collisionterm in the relaxation rate approximation selected in a form assuring currentconservation. We obtain an explicit solution for the linearized perturbation ofthe Fermi-Dirac equilibrium distribution in terms of the average relaxationrate $\kappa$. We study the resulting covariant, gauge invariant, and currentconserving form of the polarization tensor in the ultrarelativistic andnon-relativistic limits. We evaluate the susceptibility in theultrarelativistic limit and explore their dependence on $\kappa$. Finally, westudy the dispersion relations for the longitudinal and transverse poles of thepropagator. We show that for $\kappa> 2\omega_p$, where $\omega_p$ is theplasma frequency, the plasma wave modes are overdamped. In the opposite case,$\kappa \ll \omega_p$, the propagating plasma modes are weakly damped.[Journal_ref: ]
• Formanek, M., Steinmetz, A., & Rafelski, J. (2021). Motion of classical charged particles with magnetic moment in external (plane wave) EM fields. Physical Review A, 103(5), 052218. doi:https://doi.org/10.1103/PhysRevA.103.052218
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  We study the motion of a charged particle with magnetic moment in externalelectromagnetic fields utilizing covariant unification of Gilbertian andAmperian descriptions of particle magnetic dipole moment. Considering the caseof a current loop, our approach is verified by comparing classical dynamicswith the classical limit of relativistic quantum dynamics. We obtain motion ofa charged particle in the presence of an external linearly polarized EM (laser)plane wave field incorporating the effect of spin dynamics. For specificlaser-particle initial configurations, we determine that the Stern-Gerlachforce can have a cumulative effect on the trajectory of charged particles.[Journal_ref: ]
• Price, W., Formanek, M., & Rafelski, J. (2022). Radiation reaction and limiting acceleration. Physical Review D, 105(1), 016024. doi:https://doi.org/10.1103/PhysRevD.105.016024
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  We investigate the strong acceleration properties of the radiation reactionforce and identify a new and promising limiting acceleration feature in theEliezer-Ford-O'Connell model; in the strong field regime, for many fieldconfigurations, we find an upper limit to acceleration resulting in a bound tothe rate of radiation emission. If this model applies, strongly acceleratedparticles are losing energy at a much slower pace than predicted by the usualradiation reaction benchmark, the Landau-Lifshitz equation, which certainlycannot be used in this regime. We explore examples involving various "constant"electromagnetic field configurations and study particle motion in a light planewave as well as in a material medium.[Journal_ref: ]
• Rafelski, J. (2021). The muon abundance in the primordial Universe. Acta Physics Polonica B, 52(3), 277-286. doi:10.5506/APhysPolB.52.277
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  Muon abundance is required for the understanding of several fundamentalquestions regarding properties of the primordial Universe. In this paper weevaluate the production and decay rates of muons in the cosmic plasma as afunction of temperature. This allows us to determine when exactly the muonabundance disappears. When the Universe cools below the temperature$kT_\mathrm{disappear}\approx 4.135$ MeV the muon decay rate overwhelmsproduction rates and muons vanish quasi-instantaneously from the Universe.Interestingly, we show that at $T_\mathrm{disappear}$ the muon number is nearlyequal to baryon abundance.[Journal_ref: ]
• Yang, C. T., & Rafelski, J. (2022). Cosmological Strangeness Abundance. Physics Letters B, 827, 136944. doi:https://doi.org/10.1016/j.physletb.2022.136944
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  We investigate the strange particle composition of the early Universe in thehadron epoch $T_h\approx 150\ge T\ge 10$\,MeV. We study strangeness yield inthermal and chemical equilibrium constrained by prescribed entropy per baryonin a charge neutral and strangeness neutral $\langle s-\bar s\rangle$ Universe.Turning to kinetic processes in a Hubble expanding Universe, we determineconditions at which individual strangeness producing reactions fall out ofdetailed balance between decay and back-reaction strangeness production ratesin presence of decreasing temperature $T$; we allow for weak, electromagnetic,and strong interaction processes. The weak interaction$\mu^\pm+\nu_{\mu}\rightarrow K^\pm$ freezeout is at$T_f^{K^\pm}=33.8\,\mathrm{MeV}$; the electromagnetic process$l^-+l^+\rightarrow\phi$ freezeout is at $T_f^\phi=23\sim25\,\mathrm{MeV}$; andthe hadronic reaction $\pi+\pi\rightarrow K$ freezeout is at$T_f^K=19.8\,\mathrm{MeV}$.[Journal_ref: ]
• Formanek, M., Steinmetz, A., & Rafelski, J. (2020). Radiation reaction friction: Resistive material medium. Phys. Rev. D 102 056015, 102, 056015. doi:https://doi.org/10.1103/PhysRevD.102.056015
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  We explore a novel method of describing the radiation friction of particlestraveling through a mechanically resistive medium. We introduce a particlemotion induced matter warping along the path in a manner assuring that chargedparticle dynamics occurs subject to radiative energy loss described by theLarmor formula. We compare our description with the Landau-Lifshitz-like modelfor the radiation friction and show that the established model exhibitsnon-physical behavior. Our approach predicts in the presence of largemechanical friction an upper limit on radiative energy loss being equal to theenergy loss due to the mechanical medium resistance. We demonstrate thatmechanical friction due to strong interactions, for example of quarks inquark-gluon plasma, can induce significant soft photon radiation.[Journal_ref: Phys. Rev. D 102, 056015 (2020)]
• Rafelski, J., & Evans, S. (2020). Electron electromagnetic-mass melting in strong fields. Phys. Rev. D 102, 036014, 102, 036014. doi:https://journals.aps.org/prd/abstract/10.1103/PhysRevD.102.036014
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  The electron's electromagnetic (EM) and Higgs mass contents responddifferently to strong external fields. The EM mass melts entirely in thepresence of a critical external electric field, as we show explicitly using amodel. For strong quasi-constant electromagnetic fields we apply this effect tocompute an enhancement of pair production rates allowing direct measurement ofmass melting. Virtual electron mass melting using the perturbative loop QEDinsert narrows the muon anomalous magnetic moment discrepancy.
• Formanek, M., Steinmetz, A., & Rafelski, J. (2019). Classical neutral point particle in linearly polarized EM plane wave field. Plasma Physics and Controlled Fusion, 61(8), 084006. doi:https://iopscience.iop.org/journal/0741-3335/page/Special_issue_on_high_field_laser-plasma_interactions_2019
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  We study a covariant classical model of neutral point particles with magneticmoment interacting with external electromagnetic fields. Classical dynamicalequations which reproduce a correct behavior in the non-relativistic limit areintroduced. We also discuss the non-uniqueness of the covariant torqueequation. The focus of this work is on Dirac neutrino beam control. We presenta full analytical solution of the dynamical equations for a neutral pointparticle motion in the presence of an external linearly polarized EM plane wave(laser) fields. Neutrino beam control using extremely intense laser fieldscould possibly demonstrate Dirac nature of the neutrino. However, for linearlypolarized ideal laser waves we show cancellation of all leading beam controleffects.
• Rafelski, J. (2019). Magnetic Dipole Moment in Relativistic Quantum Mechanics. The European Physical Journal A, 55(3), 40. doi:https://doi.org/10.1140/epja/i2019-12715-5
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  We investigate relativistic quantum mechanics (RQM) for particles witharbitrary magnetic moment. We compare two well known RQM models: a) Diracequation supplemented with an incremental Pauli term (DP); b) Klein-Gordonequations with full Pauli EM dipole moment term (KGP). We compare exactsolutions to the external field cases in the limit of weak and strong(critical) fields for: i) homogeneous magnetic field, and ii) the Coulomb$1/r$-potential. For i) we consider the Landau energies and the Landau statesas a function of the gyromagnetic factor ($g$-factor). For ii) we investigatecontribution to the Lamb shift and the fine structure splitting. For both weaddress the limit of strong binding and show that these two formulationsgrossly disagree. We discuss possible experiments capable of distinguishingbetween KGP and DP models in laboratory. We describe impact of ourconsiderations in astrophysical context (magnetars). We introduce novel RQMmodels of magnetic moments which can be further explored.[Journal_ref: Eur. Phys. J. A (2019) 55: 40]
• Rafelski, J. (2019). Virtual axion-like particle complement to Euler-Heisenberg-Schwinger action. Physics Letters B, 791, 331-334. doi:10.1016/j.physletb.2019.03.008
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  We modify action in an external electromagnetic field to include effects ofvirtual axion-like particle (ALP) excitations. A measurable addition toQED-Euler-Heisenberg-Schwinger (EHS) action is obtained and incorporated intoexperimental constraints placed on ALP mass and coupling to two photons. Theregime of these constraints in which the ALP vacuum effect surpasses the EHSeffect is characterized. We show that probing of the virtual vacuum effectoffers an alternative method in search for physics related to ALPs.
• Rafelski, J. (2020). Discovery of Quark-Gluon-Plasma: Strangeness Diaries. The European Physical Journal Special Topics, 229(1), 1-140. doi:https://doi.org/10.1140/epjst/e2019-900263-x
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  We look from a theoretical perspective at the new phase of matter,quark-gluon plasma (QGP), the new form of nuclear matter created at hightemperature and pressure. Here I retrace the path to QGP discovery and itsexploration in terms of strangeness production and strange particle signatures.We will see the theoretical arguments that have been advanced to createinterest in this determining signature of QGP. We explore the procedure used byseveral experimental groups making strangeness production an important tool inthe search and discovery of this primordial state of matter present in theUniverse before matter in its present form was formed. We close by looking atboth the ongoing research that increases the reach of this observable to LHCenergy scale $pp$ collisions, and propose an interpretation of these unexpectedresults.
• Biro, T., Greiner, C., Muller, B., Rafelski, J., & Stocker, H. (2018). Topical Issue on Frontiers in Nuclear, Heavy Ion and Strong Field Physics. Eur. Phys. J. A, 54(2), 31. doi:https://link.springer.com/journal/10050/topicalCollection/AC_767328450720bc6d5a2cf512136a619d
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  Topical Issue on Frontiers in Nuclear, Heavy Ion and Strong Field Physics: In memoriam Walter Greiner: 29 October 1935 - 5 October 2016
• Evans, S., & Rafelski, J. (2018). Vacuum stabilized by anomalous magnetic moment. Phys. Rev. D, 98, 016006. doi:10.1103/PhysRevD.98.016006
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  An analytical result for Euler-Heisenberg effective action, valid forelectron spin $g-$factor $|g|2$ viadiscovered periodicity of the effective action. This allows for a simplifiedcomputation of vacuum instability modified by the electrons measured$g=2.002319$. We find a strong suppression of vacuum decay into electronpositron pairs when magnetic fields are dominant. The result is reminiscent ofmass catalysis by magnetic fields.[Journal_ref: Phys. Rev. D 98, 016006 (2018)]
• Formanek, M., Evans, S., Rafelski, J., Steinmetz, A., & Yang, C. (2018). Strong fields and neutral particle magnetic moment dynamics. Plasma Physics and Controlled Fusion, 60(7), 074006. doi:https://iopscience.iop.org/journal/0741-3335/page/Special_issue_on_high_field_laser-plasma_interactions
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  Interaction of magnetic moment of point particles with external electromagnetic fields experiences unresolved theoretical and experimental discrepancies. In this work we point out several issues within relativistic quantum mechanics and QED and we describe effects related to a new covariant classical model of magnetic moment dynamics. Using this framework we explore the invariant acceleration experienced by neutral particles coupled to an external plane wave field through the magnetic moment: we study the case of ultrarelativistic Dirac neutrinos with magnetic moment in the range of 10−11 to 10−20 μ B; and we address the case of slowly moving neutrons. We explore how critical accelerations for neutrinos can be experimentally achieved in laser pulse interactions. The radiation of accelerated neutrinos can serve as an important test distinguishing between Majorana and Dirac nature of neutrinos.
• Odrzywolek, A., & Rafelski, J. (2018). Classification of exoplanets according to density. Acta Physics Polonica B, 49(11), 6. doi:10.5506/APhysPolB.49.1917
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  Considering probability distribution as a function of the average density ρ¯ρ¯ computed for 424 extrasolar planets, we identify three log-normal Gaussian population components. The two most populous components at ρ¯≃0.7ρ¯≃0.7 g/cc and ρ¯≃7ρ¯≃7 g/cc are the ice/gas giants and iron/rock super-Earths, respectively. A third component at ρ¯≃30ρ¯≃30 g/cc is consistent with brown dwarfs, i.e. , electron degeneracy supported objects. We note presence of several extreme density planetary objects.
• Rafelski, J. (2018). Frontiers in Nuclear, Heavy Ion and Strong Field Physics. Eur. Phys. J. A, 54(2), 31. doi:10.1140/epja/i2018-12477-6
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  An introduction describing Walter Greiner's scientific life for the topicalvolume to be published by EPJA: This special issue of The European Physical Journal A is dedicated to one of our most distinguished colleagues, Walter Greiner (fig. 1), internationally renowned scholar, creative thinker, scientific pioneer, our teacher and friend. We focus here on Walter as eminent researcher, educator, mentor of young scientists, and founder of scientific institutions[Journal_ref: Eur. Phys. J. A 54 (2018) 31]
• Rafelski, J. (2018). Measurement of the Lorentz-FitzGerald Body Contraction. The European Physical Journal A, 54(2), 29. doi:10.1140/epja/i2018-12370-4
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  A complete foundational discussion of acceleration in context of Special Relativity is presented. Acceleration allows the measurement of a Lorentz-FitzGerald body contraction created. It is argued that in the back scattering of a probing laser beam from a relativistic flying electron cloud mirror generated by an ultra-intense laser pulse, a first measurement of a Lorentz-FitzGerald body contraction is feasible.
• Rafelski, J., Formanek, M., & Steinmetz, A. (2018). Relativistic Dynamics of Point Magnetic Moment. The European Physical Journal C, 78(1), 6. doi:10.1140/epjc/s10052-017-5493-2
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  The covariant motion of a classical point particle with magnetic moment in the presence of (external) electromagnetic fields is revisited. We are interested in understanding extensions to the Lorentz force involving point particle magnetic moment (Stern–Gerlach force) and how the spin precession dynamics is modified for consistency. We introduce spin as a classical particle property inherent to Poincaré symmetry of space-time. We propose a covariant formulation of the magnetic force based on a ‘magnetic’ 4-potential and show how the point particle magnetic moment relates to the Amperian (current loop) and Gilbertian (magnetic monopole) descriptions. We show that covariant spin precession lacks a unique form and discuss the connection to g−2 anomaly. We consider the variational action principle and find that a consistent extension of the Lorentz force to include magnetic spin force is not straightforward. We look at non-covariant particle dynamics, and present a short introduction to the dynamics of (neutral) particles hit by a laser pulse of arbitrary shape.
• , G. M., & , J. R. (2017). The Relativistic Foundations of Synchrotron Radiation. Journal of Synchrotron Radiation, Volume, 898-901.
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  Special Relativity (SR) determines the properties of synchrotron radiation,but the corresponding mechanisms are frequently misunderstood. Time dilation isoften invoked among the causes, whereas its role would violate the principlesof SR. We show that the correct explanation of the synchrotron radiationproperties is provided by a combination of the Doppler shift, not dependent ontime dilation effects, contrary to a common belief, and of the Lorentztransformation into the particle reference frame of the electromagnetic fieldof the emission-inducing device, also with no contribution from time dilation.We close by reminding the reader that much if not all of our argument has beenavailable since the inception of SR, a research discipline of its own standing.[Journal_ref: Journal of Synchrotron Radiation, Volume 24, Part 4, pages 898-901 (2017)]
• Koch, P., Muller, B., & Rafelski, J. (2017). From strangeness enhancement to quark–gluon plasma discovery. International Journal of Modern Physics A, A32(31), 1730024. doi:10.1142/S0217751X17300241
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  This is a short survey of signatures and characteristics of the quark–gluon plasma in the light of experimental results that have been obtained over the past three decades. In particular, we present an in-depth discussion of the strangeness observable, including a chronology of the experimental effort to detect QGP at CERN-SPS, BNL-RHIC, and CERN-LHC.
• Margaritondo, G., & Rafelski, J. (2017). The relativistic foundations of synchrotron radiation. Journal of Synchrotron Radiation, 24(4), 898-901. doi:https://doi.org/10.1107/S160057751700769X
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  Special relativity (SR) determines the properties of synchrotron radiation, but the corresponding mechanisms are frequently misunderstood. Time dilation is often invoked among the causes, whereas its role would violate the principles of SR. Here it is shown that the correct explanation of the synchrotron radiation properties is provided by a combination of the Doppler shift, not dependent on time dilation effects, contrary to a common belief, and of the Lorentz transformation into the particle reference frame of the electromagnetic field of the emission-inducing device, also with no contribution from time dilation. Concluding, the reader is reminded that much, if not all, of our argument has been available since the inception of SR, a research discipline of its own standing.
• Rafelski, J. (2017). The Mar(e)k of QGP: Strangeness. Acta Phys. Polon. Supp. B, 10(3), 867-893. doi:10.5506/APhysPolBSupp.10.867
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  Strangeness signature of quark–gluon plasma (QGP) is central to the exploration of baryon-dense matter: the search for the critical point and onset of deconfinement. I report on the discovery of QGP by means of strangeness: the key historical figures and their roles in this quest are introduced and the experimental results obtained are discussed. The important role of antihyperons is emphasized. The statistical hadronization model and sudden hadronization are described. Results of present day data analysis — strangeness and entropy content of a large fireball, and the universal hadronization condition describing key features of all explored collision systems — are presented.
• Labaune, C., Baccou, C., Yahia, V., Neuville, C., & Rafelski, J. (2016). Laser-initiated primary and secondary nuclear reactions in Boron-Nitride. SCIENTIFIC REPORTS, 6.
• Rafelski, J. (2016). CHARTING THE FUTURE FRONTIER(S) OF PARTICLE PRODUCTION. ACTA PHYSICA POLONICA B, 47(7), 1977-1991.
• Rafelski, J. (2016). Charting the future frontier(s) of particle production.
• Birrell, J., & Rafelski, J. (2015). Proposal for Resonant Detection of Relic Massive Neutrinos. Eur. Phys. J., C75(2), 91.
• Birrell, J., & Rafelski, J. (2015). Proposal for Resonant Detection of Relic Massive Neutrinos. The European Physical Journal C, 75, 91:1-8.
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  We present a novel method for detecting the relic neutrino background that takes advantage of structured quantum degeneracy to amplify the drag force from neutrinos scattering off a detector. Developing this idea, we present a characterization of the present day relic neutrino distribution in an arbitrary frame, including the influence of neutrino mass and neutrino reheating by \(e^+e^-\) annihilation. We present explicitly the neutrino velocity and de Broglie wavelength distributions for the case of an Earthbound observer. Considering that relic neutrinos could exhibit quantum liquid features at the present day temperature and density, we discuss the impact of neutrino fluid correlations on the possibility of resonant detection.
• Birrell, J., & Rafelski, J. (2015). Quark–gluon plasma as the possible source of cosmological dark radiation. Physics Letters B, 741, 77-81.
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  The effective number of neutrinos, NeffNeff, obtained from CMB fluctuations accounts for all effectively massless degrees of freedom present in the Universe, including but not limited to the three known neutrinos. Using a lattice-QCD derived QGP equation of state, we constrain the observed range of NeffNeff in terms of the freeze-out of unknown degrees of freedom near to quark–gluon hadronization. We explore limits on the coupling of these particles, applying methods of kinetic theory, and discuss the implications of a connection between NeffNeff and the QGP transformation for laboratory studies of QGP.
• Birrell, J., Wilkening, J., & Rafelski, J. (2014). Boltzmann Equation Solver Adapted to Emergent Chemical Non-equilibrium. J. Comput. Phys, 281, 896-916. doi:https://doi.org/10.1016/j.jcp.2014.10.056
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  We present a novel method to solve the spatially homogeneous and isotropic relativistic Boltzmann equation. We employ a basis set of orthogonal polynomials dynamically adapted to allow for emergence of chemical non-equilibrium. Two time dependent parameters characterize the set of orthogonal polynomials, the effective temperature T(t) and phase space occupation factor Υ(t). In this first paper we address (effectively) massless fermions and derive dynamical equations for T(t) and Υ(t) such that the zeroth order term of the basis alone captures the particle number density and energy density of each particle distribution. We validate our method and illustrate the reduced computational cost and the ability to easily represent final state chemical non-equilibrium by studying a model problem that is motivated by the physics of the neutrino freeze-out processes in the early Universe, where the essential physical characteristics include reheating from another disappearing particle component (e±-annihilation).
• Birrell, J., Wilkening, J., & Rafelski, J. (2015). Boltzmann equation solver adapted to emergent chemical non-equilibrium. Journal of Computational Physics, 281, 896-916. doi:10.1016/j.jcp.2014.10.056
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  We present a novel method to solve the spatially homogeneous and isotropic relativistic Boltzmann equation. We employ a basis set of orthogonal polynomials dynamically adapted to allow for emergence of chemical non-equilibrium. Two time dependent parameters characterize the set of orthogonal polynomials, the effective temperature T(t) and phase space occupation factor ϒ{hooked}(t). In this first paper we address (effectively) massless fermions and derive dynamical equations for T(t) and ϒ{hooked}(t) such that the zeroth order term of the basis alone captures the particle number density and energy density of each particle distribution. We validate our method and illustrate the reduced computational cost and the ability to easily represent final state chemical non-equilibrium by studying a model problem that is motivated by the physics of the neutrino freeze-out processes in the early Universe, where the essential physical characteristics include reheating from another disappearing particle component (e±-annihilation).
• Birrelll, J., Yang, C., & Rafelski, J. (2015). Relic neutrino freeze-out: Dependence on natural constants. Nuclear Physics B, 890, 481–517. doi:doi:10.1016/j.nuclphysb.2014.11.020
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  Analysis of cosmic microwave background radiation fluctuations favors an effective number of neutrinos, Nν>3Nν>3. This motivates a reinvestigation of the neutrino freeze-out process. Here we characterize the dependence of NνNν on the Standard Model (SM) parameters that govern neutrino freeze-out. We show that NνNν depends on a combination η of several natural constants characterizing the relative strength of weak interaction processes in the early Universe and on the Weinberg angle sin2⁡θWsin2⁡θW. We determine numerically the dependence Nν(η,sin2⁡θW)Nν(η,sin2⁡θW) and discuss these results. The extensive numerical computations are made possible by two novel numerical procedures: a spectral method Boltzmann equation solver adapted to allow for strong reheating and emergent chemical non-equilibrium, and a method to evaluate Boltzmann equation collision integrals that generates a smooth integrand.
• Rafelski, J. (2015). CR-39 track detector calibration for H, He, and C ions from 0.1-0.5 MeV up to 5 MeV for laser-induced nuclear fusion product identification. Rev. Sci. Instrum, 86, 083307. doi:http://dx.doi.org/10.1063/1.4927684
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  Laser-accelerated ion beams can be used in many applications and, especially, to initiate nuclear reactions out of thermal equilibrium. We have experimentally studied aneutronic fusion reactions induced by protons accelerated by the Target Normal Sheath Acceleration mechanism, colliding with a boron target. Such experiments require a rigorous method to identify the reaction products (alpha particles) collected in detectors among a few other ion species such as protons or carbon ions, for example. CR-39 track detectors are widely used because they are mostly sensitive to ions and their efficiency is near 100%. We present a complete calibration of CR-39 track detector for protons, alpha particles, and carbon ions. We give measurements of their track diameters for energy ranging from hundreds of keV to a few MeV and for etching times between 1 and 8 h. We used these results to identify alpha particles in our experiments on proton-boron fusion reactions initiated by laser-accelerated protons. We show that their number clearly increases when the boron fuel is preformed in a plasma state.
• Rafelski, J. (2015). Extreme states of nuclear matter — Presented at “Workshop on Future Relativistic Heavy Ion Experiments” held 7-10 October 1980 at: GSI, Darmstadt, Germany . European Physical Journal A, 51(9), 115. doi:10.1140/epja/i2015-15115-y
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  The theory of hot nuclear fireballs consisting of all possible finite-size hadronic constituents in chemical and thermal equilibrium is presented. As a complement of this hadronic gas phase characterized by maximal temperature and energy density, the quark bag description of the hadronic fireball is considered. Preliminary calculations of temperatures and mean transverse momenta of particles emitted in high multiplicity relativistic nuclear collisions together with some considerations on the observability of quark matter are offered.
• Rafelski, J. (2015). Extreme states of nuclear matter-1980. EUROPEAN PHYSICAL JOURNAL A, 51(9), 115.
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  The theory of hot nuclear fireballs consisting of all possible finite-size hadronic constituents in chemical and thermal equilibrium is presented. As a complement of this hadronic gas phase characterized by maximal temperature and energy density, the quark bag description of the hadronic fireball is considered. Preliminary calculations of temperatures and mean transverse momenta of particles emitted in high multiplicity relativistic nuclear collisions together with some considerations on the observability of quark matter are offered.
• Rafelski, J. (2015). Melting Hadrons, Boiling Quarks. Eur. Phys. J. A (, 2015) 51.
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  In the context of the Hagedorn temperature half-centenary I describe ourunderstanding of the hot phases of hadronic matter both below and above theHagedorn temperature. The first part of the review addresses many frequentlyposed questions about properties of hadronic matter in different phases, phasetransition and the exploration of quark-gluon plasma (QGP). The historicalcontext of the discovery of QGP is shown and the role of strangeness andstrange antibaryon signature of QGP illustrated. In the second part I discussthe corresponding theoretical ideas and show how experimental results can beused to describe the properties of QGP at hadronization. The material of thisreview is complemented by two early and unpublished reports containing theprediction of the different forms of hadron matter, and of the formation of QGPin relativistic heavy ion collisions, including the discussion of strangeness,and in particular strange antibaryon signature of QGP.[Journal_ref: Eur. Phys. J. A (2015) 51: 114 (and 115 and 116 for appendix/addenda)]
• Rafelski, J. (2015). Melting hadrons, boiling quarks. The European Physical Journal A, 51, 114. doi:http://link.springer.com/article/10.1140%2Fepja%2Fi2015-15114-0
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  In the context of the Hagedorn temperature half-centenary I describe our understanding of the hot phases of hadronic matter both below and above the Hagedorn temperature. The first part of the review addresses many frequently posed questions about properties of hadronic matter in different phases, phase transition and the exploration of quark-gluon plasma (QGP). The historical context of the discovery of QGP is shown and the role of strangeness and strange antibaryon signature of QGP illustrated. In the second part I discuss the corresponding theoretical ideas and show how experimental results can be used to describe the properties of QGP at hadronization. The material of this review is complemented by two early and unpublished reports containing the prediction of the different forms of hadron matter, and of the formation of QGP in relativistic heavy ion collisions, including the discussion of strangeness, and in particular strange antibaryon signature of QGP.
• Rafelski, J. (2015). New scheme to produce aneutronic fusion reactions by laser-accelerated ions. Laser and Particle Beams, 33, 117-122. doi:http://dx.doi.org/10.1017/S0263034615000178
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  The development of high-intensity lasers has opened the field of nuclear reactions initiated by laser-accelerated particles. One possible application is the production of aneutronic fusion reactions for clean fusion energy production. We propose an innovative scheme based on the use of two targets and present the first results obtained with the ELFIE facility (at the LULI Laboratory) for the proton–boron-11 (p–11B) fusion reaction. A proton beam, accelerated by the Target Normal Sheat Acceleration mechanism using a short laser pulse (12 J, 350 fs, 1.056 µm, 1019 W cm−2), is sent onto a boron target to initiate fusion reactions. The number of reactions is measured with particle diagnostics such as CR39 track-detectors, active nuclear diagnostic, Thomson Parabola, magnetic spectrometer, and time-of-flight detectors that collect the fusion products: the α-particles. Our experiment shows promising results for this scheme. In the present paper, we discuss its principle and advantages compared with another scheme that uses a single target and heating mechanisms directly with photons to initiate the same p–11B fusion reaction.
• Rafelski, J. (2015). Strangeness and phase changes in hot hadronic matter — presented  at: “Sixth High Energy Heavy Ion Study” held 28 June – 1 July 1983 at: LBNL, Berkeley, CA, USA  . Eur. Phys. J. A,, 51(9), 116. doi:10.1140/epja/i2015-15116-x
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  Two phases of hot hadronic matter are described with emphasis put on their distinction. Here the role of strange particles as a characteristic observable of the quark-gluon plasma phase is particularly explored.
• Rafelski, J. (2015). Strangeness and phase changes in hot hadronic matter - 1983. The European Physical Journal A, 51(9), 116.
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  Two phases of hot hadronic matter are described with emphasis put on their distinction. Here the role of strange particles as a characteristic observable of the quark-gluon plasma phase is particularly explored.
• Rafelski, J., & Birrelll, J. (2015). Dynamical emergence of the Universe into the false vacuum. JCAP Journal of Cosmology and Astroparticle Physics, 2015, 11.035. doi:https://doi.org/10.1088/1475-7516/2015/11/035
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  We study how the hot Universe evolves and acquires the prevailing vacuum state, demonstrating that in specific conditions which are believed to apply, the Universe becomes frozen into the state with the smallest value of Higgs vacuum field v=lang hrang, even if this is not the state of lowest energy. This supports the false vacuum dark energy Λ-model. Under several likely hypotheses we determine the temperature in the evolution of the Universe at which two vacuua v1, v2 can swap between being true and false. We evaluate the dynamical surface pressure on domain walls between low and high mass vaccua due to the presence of matter and show that the low mass state remains the preferred vacuum of the Universe.
• Rafelski, J., & Petran, M. (2015). QCD phase transition studied by means of hadron production. Phys. Part. Nucl., 46(5), 748-755.
• Rafelski, J., & Petran, M. (2015). QCD phase transition studied by means of hadron production. Physics of Particles and Nucle, 46, 748-755.
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  We address the hadronization process of a QGP fireball formed in relativistic heavy-ion collisions in the entire range of past and present heavy ion collision reaction energies. A precise method of analysis of hadron multiplicities has evolved into the “SHARE with CHARM” statistical hadronization model. Using this tool we describe successfully—over many orders of magnitude—the yield of all hadrons produced in the full range of reaction energies and centralities; exceptions are peripheral and more central collisions at low energies. The properties of the fireball final state can be understood by considering all primary hadronic particles. The dense hadron fireball created at SPS, RHIC, and LHC shows the final state differentiated solely by: i) volume changes; and ii) strangeness, (charm) flavor content. A universal hadronization pressure P = 80 ± 3 MeV/fm3 is found. The strangeness content of a large fireball as compared to entropy shows the presence of quark-gluon plasma degrees of freedom near the chemical QGP equilibrium. The 'Universal Hadronization’ condition common to SPS, RHIC, and LHC agrees with the proposed direct QGP fireball evaporation into free-streaming hadrons. Looking forward we discuss qualitatively how heavy flavor production contributes to energy stopping in the central rapidity region as function of reaction energy: the cases of LHC at full energy and future super-LHC.
• Birrell, J., Yang, C., Chen, P., & Rafelski, J. (2014). Relic neutrinos: Physically consistent treatment of effective number of neutrinos and neutrino mass. Phys. Rev., D89, 023008.
• Birrell, J., Yang, C., Chen, P., & Rafelski, J. (2014). Relic neutrinos: Physically consistent treatment of effective number of neutrinos and neutrino mass. Physical Review D - Particles, Fields, Gravitation and Cosmology, 89(2), 02300801-02300810.
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  Abstract: We perform a model independent study of the neutrino momentum distribution at freeze-out, treating the freeze-out temperature as a free parameter. Our results imply that measurement of neutrino reheating, as characterized by the measurement of the effective number of neutrinos Nν, amounts to the determination of the neutrino kinetic freeze-out temperature within the context of the standard model of particle physics where the number of neutrino flavors is fixed and no other massless (fractional) particles arise. At temperatures on the order of the neutrino mass, we show how cosmic background neutrino properties, i.e., energy density, pressure, and particle density, are modified in a physically consistent way as a function of neutrino mass and Nν. © 2014 American Physical Society.
• Hegelich, B. M., Mourou, G., & Rafelski, J. (2014). Probing the quantum vacuum with ultra intense laser pulses. Eur.Phys.J.ST, 223(6), 1093-1104.
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  This article presents: 1) The theoretical background of strong field physics and vacuum structure and stability; 2) The instrumental developments in the area of pulse lasers and considers the physics case for ultra intense laser facilities; and 3) Discussion of the applied and fundamental uses of ultra-intense lasers.
• Kuznetsova, I., & Rafelski, J. (2009). Resonance production in heavy ion collisions: Suppression of Lambda(1520) and enhancement of Sigma(1385). PHYSICAL REVIEW C, 79(1).
• Kuznetsova, I., & Rafelski, J. (2012). Electron-positron plasma drop formed by ultra-intense laser pulses. PHYSICAL REVIEW D, 85(8).
• Labun, L., & Rafelski, J. (2010). VACUUM STRUCTURE AND DARK ENERGY. INTERNATIONAL JOURNAL OF MODERN PHYSICS D, 19(14), 2299-2304.
• Petran, M., Letessier, J., Petracek, V., & Rafelski, J. (2014). Charm decay as a source of multistrange hadrons. J. Phys. Conf. Ser., 509, 012063. doi:https://doi.org/10.1088/1742-6596/509/1/012063
• Petran, M., Letessier, J., Petracek, V., & Rafelski, J. (2014). Interpretation of strange hadron production at LHC. J. Phys. Conf. Ser., 509, 012018. doi:https://doi.org/10.1088/1742-6596/509/1/012018
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  We extend the SHM analysis of hadron production results showing here consistency with the increased experimental data set, stability of the fit with regard to inclusion of finite resonance widths and 2-star hyperon resonances. We present new results on strangeness yield as a function of centrality and present their interpretation in terms of QGP inspired model of strangeness abundance in the hadronizing fireball.
• Petran, M., Letessier, J., Rafelski, J., & Torrieri, G. (2014). SHARE with CHARM. Computer Physics Communications, 185, 2056-2079.
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  Abstract: SHARE with CHARM program (SHAREv3) implements the statistical hadronization model description of particle production in relativistic heavy-ion collisions. Given a set of statistical parameters, SHAREv3 program evaluates yields and therefore also ratios, and furthermore, statistical particle abundance fluctuations. The physical bulk properties of the particle source are evaluated based on all hadrons produced, including the fitted yields. The bulk properties can be prescribed as a fit input complementing and/or replacing the statistical parameters. The modifications and improvements in the SHARE suite of programs are oriented towards recent and forthcoming LHC hadron production results including charm hadrons. This SHAREv3 release incorporates all features seen previously in SHAREv1.x and v2.x and, beyond, we include a complete treatment of charm hadrons and their decays, which further cascade and feed lighter hadron yields. This article is a complete and self-contained manual explaining and introducing both the conventional and the extended capabilities of SHARE with CHARM. We complement the particle list derived from the Particle Data Group tabulation (Beringer, 2012) composed of up, down, strange . u,d,s quarks (including resonances) with hadrons containing charm . c,c̄ quarks. We provide a table of the charm hadron decays including partial widths. The branching ratios of each charm hadron decay add to unity, which is achieved by including some charm hadron decay channels based on theoretical consideration in the absence of direct experimental information. A very successful interpretation of all available LHC results has been already obtained using this program. Program summary: . Program title: SHARE with CHARM. . Catalogue identifier: ADVD_v3_0. . Program summary URL: . http://cpc.cs.qub.ac.uk/summaries/ADVD_v3_0.html . . Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland. . Licensing provisions: Standard CPC licence, . http://cpc.cs.qub.ac.uk/licence/licence.html . . No. of lines in distributed program, including test data, etc.: 18532. . No. of bytes in distributed program, including test data, etc.: 152797. . Distribution format: tar.gz. . Programming language: FORTRAN77, C++. . Computer: PC, Intel 64-bit, 3 GB RAM (not hardware dependent). . Operating system: GNU Linux: Ubuntu, Debian, Fedora (not OS dependent). . RAM: 615 MB. . Classification: 11.2, 11.3. . External routines: Standard C++ library, CERNLIB library. . Does the new version supersede the previous version?: Yes. . Catalogue identifier of previous version: ADVD_v2_0. . Journal reference of previous version: Comput. Phys. Comm. 175 (2006) 635. . Nature of problem: . The understanding of hadron production incorporating the four . u,d,s,c quark flavors is essential for the understanding of the properties of quark-gluon plasma created in relativistic heavy-ion collisions in the large-hadron collider (LHC) energy domain. We describe hadron production by a hot fireball within the statistical hadronization model (SHM) allowing for the chemical nonequilibrium of all quark flavors individually. By fitting particle abundances subject to bulk property constraints in the source, we find the best SHM model parameters. This approach allows the testing of physical hypotheses regarding hadron production mechanisms in relativistic heavy-ion collisions, physical properties of the source at hadronization and the validity of the statistical hadronization model itself. The abundance of light hadrons made of . u,d and . s constituent quarks [2] and their fluctuations [3] were the core physics contents of the prior releases SHAREv1.x and v2.x respectively. We now consider the hadronization of the heavier charm quarks, a phenomenon of relevance in the analysis of recent and forthcoming LHC results. We introduce bulk matter constraints such as a prescribed charge to baryon ratio originating in the initial state valance . u and . d quark content of colliding nuclei. More generally, all the bulk physical properties of the particle source such as energy, entropy, pressure, strangeness content and baryon number of the fireball at hadronization are evaluated and all of these can be used as fit constraints. The charm quark degree of freedom is handled as follows: given an input number of charm quark pairs at the time of charm chemical freeze-out, we populate charm hadron yield according to rules of statistical hadronization for a prescribed set of parameters associated with the particle source, such as bulk matter fugacities. A separate charm hadronization temperature can be chosen and fitted, and as an option it is possible to make this temperature the same as the fitted hadronization temperature of . u,d,s-quarks. Charm hadron resonances decay feeding "stable" charm hadrons. These stable charm hadrons are so short-lived that within current technological detector capabilities practically all their decay products are feeding light hadron yields. These charm decay feeds are changing the abundances of produced hadrons in a pattern that differs from particle to particle. . Solution method: . SHARE with CHARM builds in its approach upon the numerical method developed for its predecessor, SHARE [2, 3] for the evaluation of the distribution of light . (u,d,s) hadrons. SHARE with CHARM distributes a prescribed number . Ncc̄ of charm . c+c̄ quarks into individual charm hadrons applying statistical hadronization rules in a newly added computation module 'CHARM' obtaining the yields evaluating appropriate series of Bessel functions. Similarly to light hadrons, the charm hadron decays are evaluated using pre-existent tables derived from PDG listing [1], proceeding from the heaviest to the lightest particle. The yields of each hadron are obtained using decay branching ratio tables of the mother particle yield-where data was not available, an appropriate theoretical model was implemented to assure that all particles decayed with 100% probability. Each of the resultant daughter hadron contributions is added to this . u,d,s hadron yield computed independently for the related set of SHM parameters in the SHARE module. The total yield is subsequently subject to the weak decays (WD) of strange hadrons. A user generated or default WD control file defines what portion of the . u,d,s particle yield decays weakly feeding other particles in turn, and which fraction given the detection capability is observed. Once final observable hadron yields are so obtained, we compare these with the experimental data aiming in an iteration to find the best set of prescribed SHM parameters for the yield of . u,d,s hadrons observed. The CHARM module is associated with two new SHM parameters, the charm hadronization temperature . Tcharm (which can be defaulted to . T obtained for the other . u,d,s hadrons) and the total yield of . Ncc̄=c,c̄ quarks, called . Ncbc. These and all other SHM parameters are discussed in the text. . Reasons for new version: . Since the release of SHAREv1 in 2004 [2] and SHAREv2 in 2006 [3], heavy-ion collision experiments underwent major development in both detector technology and collision energy. The forthcoming tracker upgrade of STAR at BNL Relativistic Heavy Ion Collider (RHIC) and the current tracking precision of ALICE at CERN Large Hadron Collider (LHC) require upgrades of the SHARE program described below. In the anticipation of significant charm abundance at LHC, SHARE with CHARM allows the study of all charm hadron production. Charm hadron decays are particularly important because they are a significant source of multistrange hadrons. The introduction of the charm component of the hadron spectrum into SHM is crucial for correct interpretation of particle production and QGP fireball properties at hadronization in heavy-ion collisions at TeV energy scale. SHARE with CHARM is an easy-to-use program, which offers a common framework for SHM analysis of all contemporary heavy-ion collision experiments for the coming years. . Summary of revisions: . The charm hadron mass spectrum and decays have been fully implemented in the provided program package. We provide a current up-to-date detailed list of charm hadrons and resonances together with their numerous decay channels within the set of fully updated input files that correspond to the present PDG status [1]. Considering the enhanced tracking capabilities of LHC experiments and similar RHIC capability, the default behavior of weak decay feed-down has been updated to not accept any weak feed-down unless specified otherwise by the user. The common framework for all contemporary heavy-ion experiments required an update of the format of the particle list and of the content to correspond to present day PDG. SHARE with CHARM is backward compatible with the previous release, SHAREv2, in terms of calculation capabilities and use of control files. However, the SHARE user may need to update and or add individual input file command lines in order to assure that same tasks are performed, considering that defaults, e.g., characterizing weak decays, have been modified. Furthermore quite a few interface improvements have been implemented and are described in detail further in this manual. They allow considerable simplification of control files. . Running time: . © 2014 Elsevier B.V.
• Petran, M., Letessier, J., Rafelski, J., & Torrieri, G. (2014). Share with charm. Computer Physics Communications, 185(7), 2056-2079. doi:10.1016/j.cpc.2014.02.026
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  SHARE with CHARM program (SHAREv3) implements the statistical hadronization model description of particle production in relativistic heavy-ion collisions. Given a set of statistical parameters, SHAREv3 program evaluates yields and therefore also ratios, and furthermore, statistical particle abundance fluctuations. The physical bulk properties of the particle source are evaluated based on all hadrons produced, including the fitted yields. The bulk properties can be prescribed as a fit input complementing and/or replacing the statistical parameters. The modifications and improvements in the SHARE suite of programs are oriented towards recent and forthcoming LHC hadron production results including charm hadrons. This SHAREv3 release incorporates all features seen previously in SHAREv1.x and v2.x and, beyond, we include a complete treatment of charm hadrons and their decays, which further cascade and feed lighter hadron yields. This article is a complete and self-contained manual explaining and introducing both the conventional and the extended capabilities of SHARE with CHARM. We complement the particle list derived from the Particle Data Group tabulation (Beringer, 2012) composed of up, down, strange u,d,s quarks (including resonances) with hadrons containing charm c,c quarks. We provide a table of the charm hadron decays including partial widths. The branching ratios of each charm hadron decay add to unity, which is achieved by including some charm hadron decay channels based on theoretical consideration in the absence of direct experimental information. A very successful interpretation of all available LHC results has been already obtained using this program. © 2014 Elsevier B.V. All rights reserved.
• Rafelski, J. (1977). Charting the future frontier(s) of particle production. Acta Physica Polonica B, Vol.
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  This short note describes the long collaborative effort between Arizona andKrak\'ow, showing some of the key strangeness signatures of quark-gluon plasma.It further presents an annotated catalog of foundational questions defining theresearch frontiers which I believe can be addressed in the foreseeable futurein the context of relativistic heavy ion collision experiments. The listincludes topics that are specific to the field, and ventures towards theknown-to-be-unknown that may have a better chance with ions as compared toelementary interactions.[Journal_ref: Acta Physica Polonica B, Vol 47 (7) p1977 (2016)]
• Rafelski, J. (2014). Inside Story: Birth of the Hagedorn temperature. CERN Courier, 54(10), 57.
• Rafelski, J., & Birrell, J. (2014). Traveling Through the Universe: Back in Time to the Quark-Gluon Plasma Era. J. Phys. Conf. Ser., 509, 012014.
• Rafelski, J., & Petran, M. (2014). Strangeness in QGP: Hadronization Pressure. Acta Phys.Polon.B Supplement, 7(1), 35-47.
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  We review strangeness as signature of quark gluon plasma (QGP) and the hadronization process of a QGP fireball formed in relativistic heavy-ion collisions in the entire range of today accessible reaction energies. We discuss energy dependence of the statistical hadronization parameters within the context of fast QGP hadronization. We find that QGP breakup occurs for all energies at the universal hadronization pressure P=80±3MeV/fm3.
• Rafelski, J., & Petran, M. (2014). Universal QGP Hadronization Conditions at RHIC and LHC. EPJ Web Conf., 78, 06004. doi:https://doi.org/10.1051/epjconf/20147806004
• Rafelski, J., Labun, L., & Birrell, J. (2013). Compact Ultradense Matter Impactors. PHYSICAL REVIEW LETTERS, 110(11).
• Birrell, J., Yang, C., Chen, P., & Rafelski, J. (2013). FUGACITY AND REHEATING OF PRIMORDIAL NEUTRINOS. MODERN PHYSICS LETTERS A, 28(40).
• Birrell, J., Yang, C., Chen, P., & Rafelski, J. (2013). Fugacity and Reheating of Primordial Neutrinos. Mod. Phys. Lett., A28, 1350188.
• Birrell, J., Yang, C., Chen, P., & Rafelski, J. (2013). Fugacity and reheating of primordial neutrinos. Modern Physics Letters A, 28(40).
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  Abstract: We clarify in a quantitative way the impact that distinct chemical T c and kinetic Tk freeze-out temperatures have on the reduction of the neutrino fugacity Υν below equilibrium, i.e. Υν
• Kuznetsova, I., & Rafelski, J. (2013). Enhanced production of Delta and Sigma (1385) resonances. PHYSICS LETTERS B, 668(2), 105-110.
• LABUN, L., & RAFELSKI, J. (2013). CRITICAL ACCELERATION AND QUANTUM VACUUM. Modern Physics Letters A, 28(03), 1340014. doi:10.1142/s0217732313400142
• Labaune, C., Baccou, C., Depierreux, S., Goyon, C., Loisel, G., Yahia, V., & Rafelski, J. (2013). Fusion reactions initiated by laser-accelerated particle beams in a laser-produced plasma.
• Labaune, C., Baccou, C., Depierreux, S., Goyon, C., Loisel, G., Yahia, V., & Rafelski, J. (2013). Fusion reactions initiated by laser-accelerated particle beams in a laser-produced plasma. NATURE COMMUNICATIONS, 4.
• Labaune, C., Baccou, C., Depierreux, S., Goyon, C., Loisel, G., Yahia, V., & Rafelski, J. (2013). Fusion reactions initiated by laser-accelerated particle beams in a laser-produced plasma. Nature Communications, 4.
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  PMID: 24104859;Abstract: The advent of high-intensity-pulsed laser technology enables the generation of extreme states of matter under conditions that are far from thermal equilibrium. This in turn could enable different approaches to generating energy from nuclear fusion. Relaxing the equilibrium requirement could widen the range of isotopes used in fusion fuels permitting cleaner and less hazardous reactions that do not produce high-energy neutrons. Here we propose and implement a means to drive fusion reactions between protons and boron-11 nuclei by colliding a laser-accelerated proton beam with a laser-generated boron plasma. We report proton-boron reaction rates that are orders of magnitude higher than those reported previously. Beyond fusion, our approach demonstrates a new means for exploring low-energy nuclear reactions such as those that occur in astrophysical plasmas and related environments. © 2013 Macmillan Publishers Limited.
• Labun, L., & Rafelski, J. (2013). Temperature of electron fluctuations in an accelerated vacuum. Modern Physics Letters A, 28(3).
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  Abstract: The electron vacuum fluctuations measured by (ψψ) do not vanish in an externally applied electric field ε. For an exactly constant field, that is for vacuum fluctuations in presence of a constant accelerating force, we show that (ψψ) has a Boson-like structure with spectral state density tanh-1(E/m) and temperature TM = eε/mπ = a v/π. Considering the vacuum fluctuations of 'classical' gyromagnetic ratio g = 1 particles we find Fermi-like structure with the same spectral state density at a smaller temperature T1 = a v/2π which corresponds to the Unruh temperature of an accelerated observer. © 2013 World Scientific Publishing Company.
• Labun, L., & Rafelski, J. (2013). Top anomalous magnetic moment and the two photon decay of Higgs boson. Phys. Rev., D88, 071301.
• Labun, L., & Rafelski, J. (2013). Top anomalous magnetic moment and the two-photon decay of the Higgs boson. PHYSICAL REVIEW D, 88(7).
• Labun, L., & Rafelski, J. (2013). Top anomalous magnetic moment and the two-photon decay of the Higgs boson. Physical Review D - Particles, Fields, Gravitation and Cosmology, 88(7).
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  Abstract: We compute the dependence of the Higgs to two-photon decay rate Γh→γγ on the top quark gyromagnetic factor gt in the heavy top limit and evaluate the expected change for one-loop SM correction to gt. Our results are general and allow consideration of further modifications of gt, and we predict the resultant Γh→γγ. © 2013 American Physical Society.
• Letessier, J., & Rafelski, J. (2013). Strangeness chemical equilibration in a quark-gluon plasma. PHYSICAL REVIEW C, 75(1).
• Petran, M., & Rafelski, J. (2013). Universal hadronization condition in heavy ion collisions at $\sqrts_\mathrm{NN}= 62$ GeV and at $\sqrts_\mathrm{NN}=2.76$ TeV. Phys. Rev., C88(2), 021901.
• Petrán, M., Letessier, J., Petráček, V., & Rafelski, J. (2013). Hadron production and quark-gluon plasma hadronization in Pb-Pb collisions at $\sqrts_{NN}=2.76$ TeV. Phys. Rev., C88(3), 034907.
• Petráň, M., & Rafelski, J. (2013). Universal hadronization condition in heavy ion collisions at √s _NN=62GeV and at √s_NN=2.76TeV. Physical Review C - Nuclear Physics, 88(2).
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  Abstract: We obtain a detailed description of all available hadron multiplicity yields in central Pb-Pb collisions at the CERN Large Hadron Collider (LHC) measured in the rapidity interval |y|
• Petráň, M., Letessier, J., Petráček, V., & Rafelski, J. (2013). Hadron production and quark-gluon plasma hadronization in Pb-Pb collisions at √s_NN=2.76 TeV. Physical Review C - Nuclear Physics, 88(3).
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  Abstract: We show that all central rapidity hadron yields measured in Pb-Pb collisions at √sNN=2.76 TeV are well described by the chemical nonequilibrium statistical hadronization model (SHM), where the chemically equilibrated quark-gluon plasma source breaks up directly into hadrons. SHM parameters are obtained as a function of centrality of colliding ions, and we compare CERN Large Hadron Collider (LHC) results with Brookhaven National Laboratory Relativistic Heavy Ion Collider (RHIC) results. We predict yields of unobserved hadrons and address antimatter production. The physical properties of the quark-gluon plasma fireball particle source show universality of hadronization conditions at LHC and RHIC. © 2013 American Physical Society.
• Rafelski, J. (2013). Connecting QGP-Heavy Ion Physics to the Early Universe. Nuclear Physics B - Proceedings Supplements, 243-244, 155-162. doi:https://doi.org/10.1016/j.nuclphysbps.2013.09.017
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  Abstract: We discuss properties and evolution of quark-gluon plasma in the early Universe and compare to laboratory heavy ion experiments. We describe how matter and antimatter emerged from a primordial soup of quarks and gluons. We focus our discussion on similarities and differences between the early Universe and the laboratory experiments. © 2013 CERN for the benefit of the authors.
• Rafelski, J. (2013). Fusion reactions initiated by laser-accelerated particle beams in a laser-produced plasma. Nature Communications. doi:https://doi.org/10.1038/ncomms3506
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  The advent of high-intensity pulsed laser technology enables the generationof extreme states of matter under conditions that are far from thermalequilibrium. This in turn could enable different approaches to generatingenergy from nuclear fusion. Relaxing the equilibrium requirement could widenthe range of isotopes used in fusion fuels permitting cleaner and lesshazardous reactions that do not produce high energy neutrons. Here we proposeand implement a means to drive fusion reactions between protons and boron-11nuclei, by colliding a laser-accelerated proton beam with a laser-generatedboron plasma. We report proton-boron reaction rates that are orders ofmagnitude higher than those reported previously. Beyond fusion, our approachdemonstrates a new means for exploring low-energy nuclear reactions such asthose that occur in astrophysical plasmas and related environments.[Journal_ref: Nature Communications 4:2506 (2013)]
• Rafelski, J., & Labun, L. (2013). Critical acceleration and quantum vacuum. Modern Physics Letters A, 28(3).
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  Abstract: Little is known about the physics frontier of strong acceleration; both classical and quantum physics need further development in order to be able to address this newly accessible area of physics. In this lecture we discuss what strong acceleration means, possible experiments using electron-laser collisions, and data available from ultra-relativistic heavy ion collisions. We review the foundations of the current understanding of charged particle dynamics in presence of critical forces and discuss the radiation reaction inconsistency in electromagnetic theory and the apparent relation with quantum physics and strong field particle production phenomena. The role of the quantum vacuum as an inertial reference frame is emphasized, as well as the absence of such a 'Machian' reference frame in the conventional classical limit of quantum field theory. © 2013 World Scientific Publishing Company.
• Rafelski, J., & Letessier, J. (2013). Particle production in root s(NN)=2.76 TeV heavy ion collisions. PHYSICAL REVIEW C, 83(5).
• Rafelski, J., Kuznetsova, I., & Letessier, J. (2013). Strangeness at the threshold of phase change. JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS, 35(4).
• Rafelski, J., Labun, L., & Birrell, J. (2013). Compact Ultradense Matter Impactors. Phys. Rev. Lett., 110(11), 111102.
• Rafelski, J., Labun, L., & Birrell, J. (2013). Compact ultradense matter impactors. Physical Review Letters, 110(11).
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  Abstract: We study interactions of meteorlike compact ultradense objects (CUDO), having nuclear or greater density, with Earth and other rocky bodies in the Solar System as a possible source of information about novel forms of matter. We study the energy loss in CUDO puncture of the body and discuss differences between regular matter and CUDO impacts. © 2013 American Physical Society.
• Torrieri, G., & Rafelski, J. (2013). Hadron resonances and phase threshold in heavy ion collisions. PHYSICAL REVIEW C, 75(2).
• Birrell, J., & Rafelski, J. (2012). Possibility of Electroweak Phase Transition at Low Temperature.
• Birrell, J., Yang, C., Chen, P., & Rafelski, J. (2012). Relic neutrinos: Physically consistent treatment of effective number of neutrinos and neutrino mass. PHYSICAL REVIEW D, 89(2).
• Dietl, C., Labun, L., & Rafelski, J. (2012). Properties of Gravitationally Bound Dark Compact Ultra Dense Objects. Phys. Lett., B709, 123-127.
• Dietl, C., Labun, L., & Rafelski, J. (2012). Properties of gravitationally bound dark compact ultra dense objects. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 709(3), 123-127.
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  Abstract: We consider compact astrophysical objects formed from dark matter fermions of mass 250 GeV to 100 TeV or from massless fermions hidden by vacuum structure of similar energy scale. These objects have maximum stable masses of sub-planetary scale and radii of micron to centimeter scale. We describe the surface gravity and tidal forces near these compact ultra dense objects, as pertinent to signatures of their collisions with visible matter objects. © 2012 Elsevier B.V.
• Fromerth, M. J., Kuznetsova, I., Labun, L., Letessier, J., & Rafelski, J. (2012). From Quark-Gluon Universe to Neutrino Decoupling: 200 < T < 2MeV. Acta Phys. Polon., B43(12), 2261-2284.
• Fromerth, M. J., Kuznetsova, I., Labun, L., Letessier, J., & Rafelski, J. (2012). From quark-gluon universe to neutrino decoupling: 200 < T < 2 MeV. Acta Physica Polonica B, 43(12), 2261-2283.
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  Abstract: The properties of the quark and hadron Universe are explored. Kinetic theory considerations are presented proving that hadron abundances after phase transformation from quarks to hadrons remain intact till abundances of hadrons become irrelevant. The hadronization process and the evolution of hadron yields are described in detail.
• Kuznetsova, I., & Rafelski, J. (2012). Electron-Positron Plasma Drop Formed by Ultra-Intense Laser Pulses. Phys. Rev., D85, 085014.
• Kuznetsova, I., & Rafelski, J. (2012). Electron-positron plasma drop formed by ultra-intense laser pulses. Physical Review D - Particles, Fields, Gravitation and Cosmology, 85(8).
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  Abstract: We study the initial properties and positron annihilation within a small electron-positron plasma drop formed by intense laser pulse energy. Such QED cascade generated plasma is, in general, far below the chemical (particle yield) equilibrium. We find that the available electrons and positrons equilibrate kinetically, yet despite relatively high particle density, the electron-positron annihilation is very slow, suggesting a rather long life span of the plasma drop. © 2012 American Physical Society.
• Kuznetsova, I., & Rafelski, J. (2012). Non-equilibrium heavy-flavored hadron yields from chemical equilibrium strangeness-rich QGP. JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS, 35(4).
• Labun, L., & Rafelski, J. (2012). Acceleration and Vacuum Temperature. Phys. Rev., D86, 041701.
• Labun, L., & Rafelski, J. (2012). Acceleration and vacuum temperature. Physical Review D - Particles, Fields, Gravitation and Cosmology, 86(4).
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  Abstract: The quantum fluctuations of an "accelerated" vacuum state, that is, vacuum fluctuations in the presence of a constant electromagnetic field, can be described by the temperature T M. Considering T M for the gyromagnetic factor g=1 we show that T M(g=1)=T U, where T U is the Unruh temperature experienced by an accelerated observer. We conjecture that both particle production and nonlinear field effects inherent in the Unruh accelerated observer case are described by the case g=1 QED of strong fields. We present rates of particle production for g=0, 1, 2 and show that the case g=1 is experimentally distinguishable from g=0, 2. Therefore, either accelerated observers are distinguishable from accelerated vacuum or there is unexpected modification of the theoretical framework. © 2012 American Physical Society.
• Labun, L., & Rafelski, J. (2012). Higgs two-gluon decay and the top-quark chromomagnetic moment.
• Labun, L., & Rafelski, J. (2012). Nonlinear electromagnetic forces in astrophysics. Acta Physica Polonica B, 43(12), 2237-2250.
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  Abstract: Electromagnetism becomes a nonlinear theory having (effective) photon- photon interactions due at least to electron-positron fluctuations in the vacuum. We discuss the consequences of the nonlinearity for the force felt by a charge probe particle, and compare the impact of Euler-Kockel QED effective nonlinearity to the possibility of Born-Infeld-type nonlinearity.
• Labun, L., & Rafelski, J. (2012). Planetary Impacts by Clustered Quark Matter Strangelets. Acta Phys. Polon. Supp., 5, 381-386.
• Labun, L., & Rafelski, J. (2012). Temperature of Electron Fluctuations in an Accelerated Vacuum.
• Miller, G. A., Thomas, A. W., Carroll, J. D., & Rafelski, J. (2012). Resolution of the proton radius puzzle via off-shell form factors. AIP Conf. Proc., 1441, 150-152.
• Miller, G. A., Thomas, A. W., Carroll, J. D., & Rafelski, J. (2012). Resolution of the proton radius puzzle via off-shell form factors. AIP Conference Proceedings, 1441, 150-152.
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  Abstract: We show that off-mass-shell effects arising from the internal structure of the proton provide a new proton polarization mechanism in the Lamb shift, proportional to the lepton mass to the fourth power. This effect is capable of resolving the current puzzle regarding the difference in the proton radius extracted from muonic compared with electronic hydrogen experiments. These off-mass-shell effects could be probed in several other experiments. A significant ambiguity appearing in dispersion relation evaluations of the proton polarizability contribution to the Lamb shift is noted. © 2012 American Institute of Physics.
• Miller, G. A., Thomas, A. W., Carroll, J. D., & Rafelski, J. (2012). What's New with the Neutron and Proton. Few-Body Systems, 52(3-4), 357-366.
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  Abstract: The existence and importance of the proton radius puzzle, observed via a Lamb shift measurement in muonic atoms, is discussed. Possible resolutions of the puzzle are discussed. Then the broader question of the meaning of the proton radius is addressed and examples of correctly defined charge densities are presented. © 2011 Springer-Verlag.
• Miller, G. A., Thomas, A. W., Carroll, J. D., & Rafelski, J. (2012). What's new with the neutron and proton. Few Body Syst., 52, 357-366.
• Miller, G. A., Thomas, A., Carroll, J. D., & Rafelski, J. (2012). What's New with the Neutron and Proton. FEW-BODY SYSTEMS, 52(3-4), 357-366.
• Petran, M., Letessier, J., Petracek, V., & Rafelski, J. (2012). Strangeness Production in Au-Au collisions at $\sqrts_{NN}=62.4$ GeV. Acta Phys. Polon. Supp., 5, 255-262.
• Rafelski, J. (2012). Quarks in the Universe. INTERNATIONAL JOURNAL OF MODERN PHYSICS E-NUCLEAR PHYSICS, 16(3), 813-828.
• Rafelski, J. (2012). Strangeness and Quark--Gluon Plasma. Acta Phys. Polon., B43, 829.
• Rafelski, J. (2012). Strangeness and Quark--Gluon Plasma. Acta Physica Polonica B vol..
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  I review the foundational motivation which led us to the ultra relativisticheavy ion collision research at SPS, RHIC and now LHC: the quantum vacuumstructure; the deconfined nature of quark-gluon plasma (QGP) phase filling theUniverse for the first 30$\mu$s after the big-bang; the origin of stable mattermass; and of the origin of flavor. The special role of strangeness enhancementand strange antibaryon signature is highlighted. It is shown how hadronproduction can be used to determine the properties of QGP, and how thethreshold energy for QGP formation is determined.[Journal_ref: Acta Physica Polonica B vol. 43 (2012) page 829]
• Rafelski, J. (2012). Strangeness and quark-gluon plasma. Acta Physica Polonica B, 43(4), 829-842.
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  Abstract: I review the foundational motivations which led us to the ultra relativistic heavy ion collision research at SPS, RHIC and now LHC: the quantum vacuum structure; the deconfined nature of the quark-gluon plasma (QGP) phase filling the Universe for the first 30 μs after the Big Bang; the origin of mass of stable matter; and the origin of flavor. The special roles of strangeness enhancement and strange antibaryon signature are highlighted. It is shown how hadron production can be used to determine the properties of QGP and how the threshold energy for QGP formation is determined.
• Rafelski, J., & Labun, L. (2012). A Cusp in QED at g=2.
• Rafelski, J., & Labun, L. (2012). Critical Acceleration and Quantum Vacuum.
• Rafelski, J., & Letessier, J. (2012). Critical hadronization pressure. JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS, 36(6).
• Rafelski, J., Dietl, C., & Labun, L. (2012). Compact Ultradense Objects in the Solar System. Acta Phys. Polon., B43(12), 2251-2260.
• Rafelski, J., Dietl, C., & Labun, L. (2012). Compact ultra dense objects in the solar system. Acta Physica Polonica B, 43(12), 2251-2259.
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  Abstract: We describe properties and gravitational interactions of meteor-mass and greater compact ultra dense objects with nuclear density or greater (CUDOs). We discuss possible enclosure of CUDOs in comets and the stability of these objects on impact with the Earth and Sun showing that the hypothesis of a CUDO core helps resolve issues challenging the understanding of a few selected cometary impacts.
• Carroll, J. D., Thomas, A. W., Miller, G. A., & Rafelski, J. (2011). Non-perturbative Analysis of the Influence of the Proton Magnetization and Charge Densities on the Hyperfine Splitting of Muonic Hydrogen.
• Carroll, J. D., Thomas, A. W., Rafelski, J., & Miller, G. A. (2011). Non-Perturbative Relativistic Calculation of the Muonic Hydrogen Spectrum. Phys. Rev., A84, 012506.
• Carroll, J. D., Thomas, A. W., Rafelski, J., & Miller, G. A. (2011). Nonperturbative relativistic calculation of the muonic hydrogen spectrum. PHYSICAL REVIEW A, 84(1).
• Carroll, J. D., Thomas, A. W., Rafelski, J., & Miller, G. A. (2011). Nonperturbative relativistic calculation of the muonic hydrogen spectrum. Physical Review A - Atomic, Molecular, and Optical Physics, 84(1).
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  Abstract: We investigate the muonic hydrogen 2P3/2F=2 to 2S1/2F=1 transition through a precise, nonperturbative numerical solution of the Dirac equation including the finite-size Coulomb force and finite-size vacuum polarization. The results are compared with earlier perturbative calculations of (primarily) and experimental results recently presented by Pohl, in which this very comparison is interpreted as requiring a modification of the proton charge radius from that obtained in electron scattering and electronic hydrogen analyses. We find no significant discrepancy between the perturbative and nonperturbative calculations, and we present our results as confirmation of the perturbative methods. © 2011 American Physical Society.
• Carroll, J. D., Thomas, A. W., Rafelski, J., & Miller, G. A. (2011). Proton form-factor dependence of the finite-size correction to the Lamb shift in muonic hydrogen.
• Carroll, J. D., Thomas, A. W., Rafelski, J., & Miller, G. A. (2011). The Radius of the Proton: Size Does Matter. AIP Conf. Proc., 1354, 25-31.
• Carroll, J. D., Thomas, A. W., Rafelski, J., & Miller, G. A. (2011). The radius of the proton: Size does matter. AIP Conference Proceedings, 1354, 25-31.
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  Abstract: The measurement by Pohl et al. [1] of the 2S1/2F=1 to 2P3/2F=2 transition in muonic hydrogen and the subsequent analysis has led to a conclusion that the rms charge radius of the proton differs from the accepted (CODATA [2]) value by approximately 4%, leading to a 4.9σ discrepancy. We investigate the muonic hydrogen spectrum relevant to this transition using bound-state QED with Dirac wave-functions and comment on the extent to which the perturbation-theory analysis which leads to the above conclusion can be confirmed. © 2011 American Institute of Physics.
• Dietl, C., Labun, L., & Rafelski, J. (2011). Properties of gravitationally bound dark compact ultra dense objects. PHYSICS LETTERS B, 709(3), 123-127.
• Kuznetsova, I., Habs, D., & Rafelski, J. (2011). Pion and muon production in e(-), e(+), gamma plasma. PHYSICAL REVIEW D, 78(1).
• Labun, L., & Rafelski, J. (2011). Pair Production from Asymmetric Head-on Laser Collisions.
• Labun, L., & Rafelski, J. (2011). Spectra of Particles from Laser-Induced Vacuum Decay. Phys. Rev., D84, 033003.
• Labun, L., & Rafelski, J. (2011). Spectra of particles from laser-induced vacuum decay. PHYSICAL REVIEW D, 84(3).
• Labun, L., & Rafelski, J. (2011). Spectra of particles from laser-induced vacuum decay. Physical Review D - Particles, Fields, Gravitation and Cosmology, 84(3).
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  Abstract: The spectrum of electrons and positrons originating from vacuum decay occurring in the collision of two noncollinear laser pulses is obtained. It displays high energy, highly collimated particle bunches traveling in a direction separate from the laser beams. This result provides an unmistakable signature of the vacuum-decay phenomenon and could suggest a new avenue for development of high energy electron and/or positron beams. © 2011 American Physical Society.
• Miller, G. A., Thomas, A. W., Carroll, J. D., & Rafelski, J. (2011). Natural Resolution of the Proton Size Puzzle. Phys. Rev., A84, 020101.
• Miller, G. A., Thomas, A. W., Carroll, J. D., & Rafelski, J. (2011). Toward a resolution of the proton size puzzle. PHYSICAL REVIEW A, 84(2).
• Miller, G. A., Thomas, A. W., Carroll, J. D., & Rafelski, J. (2011). Toward a resolution of the proton size puzzle. Physical Review A - Atomic, Molecular, and Optical Physics, 84(2).
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  Abstract: We show that off-mass-shell effects arising from the internal structure of the proton provide a new proton polarization mechanism in the Lamb shift, proportional to the lepton mass to the fourth power. This effect is capable of resolving the current puzzle regarding the difference in the proton radius extracted from muonic compared with electronic hydrogen experiments. These off-mass-shell effects could be probed in several other experiments. A significant ambiguity appearing in dispersion relation evaluations of the proton polarizability contribution to the Lamb shift is noted. © 2011 American Physical Society.
• Rafelski, J., & Letessier, J. (2011). Particle Production in s_NN = 2.76 TeV Heavy Ion Collisions. Phys. Rev., C83, 054909.
• Rafelski, J., & Letessier, J. (2011). Particle production in √s_NN=2.76 TeV heavy ion collisions. Physical Review C - Nuclear Physics, 83(5).
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  Abstract: We obtain within the statistical hadronization model (SHM) the hadron yields dh/dy in heavy ion reactions at √sNN=2.76 TeV. We discuss the dependence both on hadronization temperature T and on critical hadronization pressure P. We consider observables distinguishing the hadronization models and conditions. © 2011 American Physical Society.
• Hadad, Y., Labun, L., Rafelski, J., Elkina, N., Klier, C., & Ruhl, H. (2010). Effects of Radiation-Reaction in Relativistic Laser Acceleration. Phys. Rev., D82, 096012.
• Hadad, Y., Labun, L., Rafelski, J., Elkina, N., Klier, C., & Ruhl, H. (2010). Effects of radiation reaction in relativistic laser acceleration. PHYSICAL REVIEW D, 82(9).
• Hadad, Y., Labun, L., Rafelski, J., Elkina, N., Klier, C., & Ruhl, H. (2010). Effects of radiation reaction in relativistic laser acceleration. Physical Review D - Particles, Fields, Gravitation and Cosmology, 82(9).
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  Abstract: The goal of this paper is twofold: to explore the response of classical charges to electromagnetic force at the level of unity in natural units and to establish a criterion that determines physical parameters for which the related radiation-reaction effects are detectable. In pursuit of this goal, the Landau-Lifshitz equation is solved analytically for an arbitrary (transverse) electromagnetic pulse. A comparative study of the radiation emission of an electron in a linearly polarized pulse for the Landau-Lifshitz equation and for the Lorentz force equation reveals the radiation-reaction-dominated regime, in which radiation-reaction effects overcome the influence of the external fields. The case of a relativistic electron that is slowed down by a counterpropagating electromagnetic wave is studied in detail. We further show that when the electron experiences acceleration of order unity, the dynamics of the Lorentz force equation, the Landau-Lifshitz equation and the Lorentz-Abraham-Dirac equation all result in different radiation emission that could be distinguished in experiment. Finally, our analytic and numerical results are compared with those appearing in the literature. © 2010 The American Physical Society.
• Kuznetsova, I., & Rafelski, J. (2010). Unstable Hadrons in Hot Hadron Gas in Laboratory and in the Early Universe. Phys. Rev., C82, 035203.
• Kuznetsova, I., & Rafelski, J. (2010). Unstable hadrons in hot hadron gas: In the laboratory and in the early Universe. PHYSICAL REVIEW C, 82(3).
• Kuznetsova, I., & Rafelski, J. (2010). Unstable hadrons in hot hadron gas: In the laboratory and in the early Universe. Physical Review C - Nuclear Physics, 82(3).
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  Abstract: We study kinetic master equations for chemical reactions involving the formation and the natural decay of unstable particles in a thermal bath. We consider the decay channel of one into two particles and the inverse process, fusion of two thermal particles into one. We present the master equations for the evolution of the density of the unstable particles in the early Universe. We obtain the thermal invariant reaction rate using as an input the free space (vacuum) decay time and show the medium quantum effects on π+πρ reaction relaxation time. As another laboratory example we describe the K+K process in thermal hadronic gas in heavy-ion collisions. A particularly interesting application of our formalism is the π0γ+γ process in the early Universe. We also explore the physics of π± and μ± freeze-out in the Universe. © 2010 The American Physical Society.
• Kuznetsova, I., Habs, D., & Rafelski, J. (2010). Thermal reaction processes in a relativistic QED plasma drop. PHYSICAL REVIEW D, 81(5).
• Kuznetsova, I., Habs, D., & Rafelski, J. (2010). Thermal reaction processes in a relativistic QED plasma drop. Phys. Rev., D81, 053007.
• Kuznetsova, I., Habs, D., & Rafelski, J. (2010). Thermal reaction processes in a relativistic QED plasma drop. Physical Review D - Particles, Fields, Gravitation and Cosmology, 81(5).
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  Abstract: The equilibrium size and temperature limits of thermally and chemically equilibrated e+e-γ plasma drops are investigated at a given energy content. For a plasma to be equilibrated it must be opaque to electron and photon interactions. The opaqueness condition is determined by comparing plasma size with the mean free electron and photon paths. We calculate those paths using thermal Lorentz-invariant reaction rates for pair production and electron (positron) and photon scattering. The range of the corresponding plasma temperature and size is evaluated numerically. Considering the energy and size we find that the opaque and equilibrated plasma drop may be experimentally attainable. © 2010 The American Physical Society.
• Labun, L., & Rafelski, J. (2010). Dark Energy Simulacrum in Nonlinear Electrodynamics. Phys. Rev., D81, 065026.
• Labun, L., & Rafelski, J. (2010). Dark energy simulacrum in nonlinear electrodynamics. PHYSICAL REVIEW D, 81(6).
• Labun, L., & Rafelski, J. (2010). Dark energy simulacrum in nonlinear electrodynamics. Physical Review D - Particles, Fields, Gravitation and Cosmology, 81(6).
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  Abstract: Quasiconstant external fields in nonlinear electromagnetism generate a global contribution proportional to gμν in the energy-momentum tensor, thus a simulacrum of dark energy. To provide a thorough understanding of the origin and strength of its effects, we undertake a complete theoretical and numerical study of the energy-momentum tensor Tμν for nonlinear electromagnetism. The Euler-Heisenberg nonlinearity due to quantum fluctuations of spinor and scalar matter fields is considered and contrasted with the properties of classical nonlinear Born-Infeld electromagnetism. We address modifications of charged particle kinematics by strong background fields. © 2010 The American Physical Society.
• Labun, L., & Rafelski, J. (2010). QED Energy-Momentum Trace as a Force in Astrophysics. Phys. Lett., B687, 133-138.
• Labun, L., & Rafelski, J. (2010). QED energy-momentum trace as a force in astrophysics. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 687(2-3), 133-138.
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  Abstract: We study the properties of the trace T of the QED energy-momentum tensor in the presence of quasi-constant external electromagnetic fields. We exhibit the origin of T in the quantum nonlinearity of the electromagnetic theory. We obtain the quantum vacuum fluctuation-induced interaction of a particle with the field of a strongly magnetized compact stellar object. © 2010 Elsevier B.V. All rights reserved.
• Labun, L., & Rafelski, J. (2010). Strong Field Physics: Probing Critical Acceleration and Inertia with Laser Pulses and Quark-Gluon Plasma. Acta Phys. Polon., B41, 2763-2783.
• Labun, L., & Rafelski, J. (2010). Strong field physics: Probing critical acceleration and inertia with laser pulses and Quark-Gluon plasma. Acta Physica Polonica B, 41(12), 2763-2783.
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  Abstract: Understanding physics in domains of critical (quantum unstable) fields requires investigating the classical and quantum particle dynamics at the critical acceleration, u̇ → 1 [natural units]. This regime of physics remains today experimentally practically untested. Particle and laser pulse collision experiments reaching critical acceleration are becoming feasible. Ultra-relativistic heavy ion collisions breach the critical domain but are complicated by the presence of much other physics. The infamous problem of radiation reaction and the challenging environment of quantum vacuum instability arising in the high field domain signal the need for a thorough redress of the present theoretical framework.
• Labun, L., & Rafelski, J. (2010). Vacuum Structure and Dark Energy. Int. J. Mod. Phys., D19, 2299-2304.
• Labun, L., & Rafelski, J. (2010). Vacuum structure and dark energy. International Journal of Modern Physics D, 19(14), 2299-2304.
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  Abstract: We consider that the universe is trapped in an excited vacuum state and the resulting excitation energy provides the observed dark energy. We explore the conditions under which this situation can arise from physics already known. Considering the example of how macroscopic quantum electrodynamic fields alter the vacuum structure, we find that the energy scale 1 meV1 eV is particularly interesting. We discuss how dark energy of this form is accessible to laboratory experiments. © 2010 World Scientific Publishing Company.
• Labun, L., & Rafelski, J. (2010). Vacuum-decay time in strong external fields. PHYSICAL REVIEW D, 79(5).
• Labun, L., Hadad, Y., & Rafelski, J. (2010). Horizons of strong field physics. AIP Conference Proceedings, 1228, 39-53.
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  Abstract: Discussing the limitations on the validity of classical electrodynamics, we show that present day laser pulse technology applied to head-on-collisionswith relativistic electrons generates fields strong enough to permit experimentation at the limits of validity of the Lorentz force, and the development of experimental tests of Mach's principle. We also discuss more distant opportunities for exploring the nature of laws of physics and the vacuum structure. We then conclude that the predictions of quantum electrodynamics in the presence of critical fields are not completely satisfactory and argue that the study of Laser materialization into particle pairs opens a new domain of quantum electrodynamics. © 2010 American Institute of Physics.
• Petran, M., & Rafelski, J. (2010). Multistrange Particle Production and the Statistical Hadronization Model. Phys. Rev., C82, 011901.
• Petran, M., Letessier, J., Petracek, V., & Rafelski, J. (2010). Hadron production and quark-gluon plasma hadronization in Pb-Pb collisions at root s(NN)=2.76 TeV. PHYSICAL REVIEW C, 88(3).
• Petran, M., Letessier, J., Petracek, V., & Rafelski, J. (2010). Statistical Hadronization of Multistrange Particles. Acta Phys. Polon., B41, 2785-2797.
• Petráñ, M., Letessier, J., Petráček, V., & Rafelski, J. (2010). Statistical hadronization of multistrange particles. Acta Physica Polonica B, 41(12), 2785-2797.
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  Abstract: We study multistrange hadrons produced in NA49 and STAR experiments at center of mass energies varying from √SNN = 7.61 GeV to 200 GeV. We show that the yields of Ξ, Ξ̄ and φ can help to constrain the physical conditions present in the hot dense fireball source of these multistrange hadrons created in heavy ion collision. We address the question of chemical equilibrium of individual quark flavors before and after hadronization and offer a few predictions for LHC.
• Petráň, M., & Rafelski, J. (2010). Multistrange particle production and the statistical hadronization model. Physical Review C - Nuclear Physics, 82(1).
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  Abstract: We consider the chemical freeze-out of Ξ, Ξ̄, and multistrange hadrons within a statistical hadronization model inspired approach. We study particle yields across a wide range of reaction energy and centrality from NA49 at the Super Proton Synchrotron (SPS) and the Solenoidal Tracker at RHIC (STAR) experiments. We constrain the physical conditions present in the fireball source of strange hadrons and anticipate results expected at the Large Hadron Collider (LHC). © 2010 The American Physical Society.
• Rafelski, J. (2010). Vacuum Structure and Dark Energy. Int.J.Mod.Phys.D, 19, 2299-2304.
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  We consider that the universe is trapped in an excited vacuum state and theresulting excitation energy provides the observed dark energy. We explore theconditions under which this situation can arise from physics already known.Considering the example of how macroscopic QED fields alter the vacuumstructure, we find that the energy scale 1 meV --- 1 eV is particularlyinteresting. We discuss how dark energy of this form is accessible tolaboratory experiments.[Journal_ref: Int.J.Mod.Phys.D19:2299-2304,2010]
• Rafelski, J., & Labun, L. (2010). CRITICAL ACCELERATION AND QUANTUM VACUUM. MODERN PHYSICS LETTERS A, 28(3).
• Rafelski, J., Labun, L., & Hadad, Y. (2010). Horizons of Strong Field Physics. AIP Conf. Proc., 1228, 39-53.
• Kuznetsova, I., & Rafelski, J. (2009). Resonance Production in Heavy Ion Collisions: Suppression of Lambda(1520) and Enhancement of Sigma(1385). Phys. Rev., C79, 014903.
• Kuznetsova, I., & Rafelski, J. (2009). Resonance production in heavy ion collisions: Suppression of ≈(1520) and enhancement of σ(1385). Physical Review C - Nuclear Physics, 79(1).
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  Abstract: We investigate the yield of ≈(1520) resonance in heavy ion collisions within the framework of a kinetic master equation without the assumption of chemical equilibrium. We show that reactions such as ≈(1520)+a σ* can favor σ* production, thereby decreasing the ≈(1520) yield. Within the same approach we thus find a yield enhancement for σ(1385) and a yield suppression for ≈(1520). © 2009 The American Physical Society.
• Kuznetsova, I., Letessier, J., & Rafelski, J. (2009). Resonances Do Not Equilibrate. Acta Phys. Polon., B40, 1013-1024.
• Kuznetsova, I., Letessier, J., & Rafelski, J. (2009). Resonances do not equilibrate. Acta Physica Polonica B, 40(4), 1013-1024.
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  Abstract: We discuss, in qualitative and quantitative fashion, the yields of hadron resonances. We show that these yields, in general, are not in chemical equilibrium. We evaluate the non-equilibrium abundances in a dynamic model implementing the 1 + 2 ↔ 3 resonance formation reactions. Due to the strength of these reactions, we show the Σ(1385) enhancement, and the Λ(1520) suppression explicitly.
• Labun, L., & Rafelski, J. (2009). TEMPERATURE OF ELECTRON FLUCTUATIONS IN AN ACCELERATED VACUUM. MODERN PHYSICS LETTERS A, 28(3).
• Labun, L., & Rafelski, J. (2009). Vacuum Decay Time in Strong External Fields. Phys. Rev., D79, 057901.
• Labun, L., & Rafelski, J. (2009). Vacuum-decay time in strong external fields. Physical Review D - Particles, Fields, Gravitation and Cosmology, 79(5).
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  Abstract: We consider dynamics of vacuum decay and particle production in the context of short pulse laser experiments. We identify and evaluate the invariant "materialization time," τ, the time scale for the conversion of an electromagnetic field energy into particles and compare to the laser related time scales. © 2009 The American Physical Society.
• Rafelski, J., & Letessier, J. (2009). Critical Hadronization Pressure. J. Phys., G36, 064017.
• Rafelski, J., & Letessier, J. (2009). Critical hadronization pressure. Journal of Physics G: Nuclear and Particle Physics, 36(6).
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  Abstract: We discuss the bulk properties of QGP produced at the RHIC obtained at time of hadronization. We argue that hadronization of a quark-gluon plasma occurs at a critical pressure near to 82 MeV fm-3, obtained for the SPS energy range. © 2009 IOP Publishing Ltd.
• Rafelski, J., Labun, L., Hadad, Y., & Chen, P. (2009). Quantum Vacuum Structure and Cosmology. eCONF, C0906083, 26.
• Steinke, S., & Rafelski, J. (2009). Quantum collective QCD string dynamics. JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS, 32(12), S455-S460.
• Zayakin, A. V., & Rafelski, J. (2009). Confinement property in SU(3) gauge theory. Physical Review D - Particles, Fields, Gravitation and Cosmology, 80(3).
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  Abstract: We study the confinement property of the pure SU(3) gauge theory, combining in this effort the nonperturbative gluon and ghost propagators obtained as solutions of Dyson-Schwinger equations with solutions of an integral ladder diagram summation type equation for the Wilson loop. We obtain the string potential and effective UV coupling. © 2009 The American Physical Society.
• Zayakin, A. V., & Rafelski, J. (2009). The Confinement Property in SU(3) Gauge Theory. Phys. Rev., D80, 034024.
• Zayakin, A. V., Khandramai, V., & Rafelski, J. (2009). Quark Condensate and Effective Action from Dyson- Schwinger Equations.
• Armesto, N., Borghini, N., Jeon, S., Wiedemann, U. A., Abreu, S., Akkelin, S. V., Alam, J., Albacete, J. L., Andronic, A., Antonov, D., Arleo, F., Armesto, N., Arsene, I. C., Barnafoeldi, G. G., Barrette, J., Baeuchle, B., Becattini, F., Betz, B., Bleicher, M., , Bluhm, M., et al. (2008). Heavy-ion collisions at the LHC-Last call for predictions. JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS, 35(5).
• Armesto, N., Borghini, N., Jeon, S., Wiedemann, U. A., Abreu, S., Akkelin, S. V., Alam, J., Albacete, J. L., Andronic, A., Antonov, D., Arleo, F., Armesto, N., Arsene, I. C., Barnaföldi, G., Barrette, J., Bäuchle, B., Becattini, F., Betz, B., Bleicher, M., , Bluhm, M., et al. (2008). Heavy-ion collisions at the LHC - Last call for predictions. Journal of Physics G: Nuclear and Particle Physics, 35(5).
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  Abstract: This writeup is a compilation of the predictions for the forthcoming Heavy Ion Program at the Large Hadron Collider, as presented at the CERN Theory Institute 'Heavy Ion Collisions at the LHC - Last Call for Predictions', held from 14th May to 10th June 2007. © 2008 IOP Publishing Ltd.
• Armesto, N., Borghini, N., Jeon, S., Wiedemann, U. A., Abreu, S., Akkelin, V., Alam, J., Albacete, J. L., Andronic, A., Antonov, D., & others, . (2008). Heavy Ion Collisions at the LHC - Last Call for Predictions. J. Phys., G35, 054001.
• Kuznetsova, I., & Rafelski, J. (2008). Enhanced Production of Delta and Sigma(1385) Resonances. Phys. Lett., B668, 105-110.
• Kuznetsova, I., & Rafelski, J. (2008). Enhanced production of Δ and Σ (1385) resonances. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 668(2), 105-110.
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  Abstract: Yields of Δ (1230), Σ (1385) resonances produced in heavy ion collisions are studied within the framework of a kinetic master equation. The time evolution is driven by the process Δ ↔ N π, Σ (1385) ↔ Λ π. We obtain resonance yield both below and above chemical equilibrium, depending on initial hadronization condition and separation of kinetic and chemical freeze-out. © 2008 Elsevier B.V. All rights reserved.
• Kuznetsova, I., & Rafelski, J. (2008). Non-Equilibrium Heavy Flavored Hadron Yields from Chemical Equilibrium Strangeness-Rich QGP. J. Phys., G35, 044043.
• Kuznetsova, I., & Rafelski, J. (2008). Non-equilibrium heavy-flavored hadron yields from chemical equilibrium strangeness-rich QGP. Journal of Physics G: Nuclear and Particle Physics, 35(4).
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  Abstract: The yields of heavy-flavored hadrons emitted from strangeness-rich QGP are evaluated within the chemical non-equilibrium statistical hadronization model, conserving strangeness, charm and entropy yields at hadronization. © 2008 IOP Publishing Ltd.
• Kuznetsova, I., Habs, D., & Rafelski, J. (2008). Pion and muon production in e-, e+, gamma plasma. Phys. Rev., D78, 014027.
• Kuznetsova, I., Habs, D., & Rafelski, J. (2008). Pion and muon production in e-, e+, γ plasma. Physical Review D - Particles, Fields, Gravitation and Cosmology, 78(1).
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  Abstract: We study production and equilibration of pions and muons in relativistic electron-positron-photon plasma at a temperature of T mμ, mπ. We argue that the observation of pions and muons can be a diagnostic tool in the study of the initial properties of such a plasma formed by means of strong laser fields. Conversely, properties of muons and pions in a thermal environment become accessible to precise experimental study. © 2008 The American Physical Society.
• Letessier, J., & Rafelski, J. (2008). Hadron production and phase changes in relativistic heavy ion collisions. Eur. Phys. J., A35, 221-242.
• Letessier, J., & Rafelski, J. (2008). Hadron production and phase changes in relativistic heavy-ion collisions. EUROPEAN PHYSICAL JOURNAL A, 35(2), 221-242.
• Letessier, J., & Rafelski, J. (2008). Hadron production and phase changes in relativistic heavy-ion collisions. The European Physical Journal A.
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  Abstract: We study soft hadron production in relativistic heavy-ion collisions in a wide range of reaction energy, 4.8 GeV < {Mathematical expression} < 200GeV, and make predictions about yields of particles using the statistical hadronization model. In fits to experimental data, we obtain both the statistical parameters as well as physical properties of the hadron source. We identify the properties of the fireball at the critical energy threshold, 6.26 GeV < {Mathematical expression} < 7.61GeV, marking for higher energies the hadronization of an entropy-rich phase. In terms of the chemical composition, one sees a phase which at low energy is chemically under-saturated, and which turns into a chemically over-saturated state persisting up to the maximum accessible energy. Assuming that there is no change in physical mechanisms in the energy range 15 > {Mathematical expression}≥200GeV, we use continuity of particle yields and statistical parameters to predict the hadron production at {Mathematical expression} = 62.4GeV, and obtain total yields of hadrons at {Mathematical expression} = 130GeV. We consider, in depth, the pattern we uncover within the hadronization condition, and discuss possible mechanisms associated with the identified rapid change in system properties at {Mathematical expression}. We propose that the chemically over-saturated 2 + 1 flavor hadron matter system undergoes a 1st-order phase transition. © 2008 Società Italiana di Fisica and Springer-Verlag.
• Petran, M., & Rafelski, J. (2008). Universal hadronization condition in heavy ion collisions at root s(NN)=62 GeV and at root s(NN)=2.76 TeV. PHYSICAL REVIEW C, 88(2).
• Rafelski, J. (2008). Strangeness Enhancement: Challenges and Successes. Eur. Phys. J. ST, 155, 139-166.
• Rafelski, J. (2008). Strangeness Enhancement: Challenges and Successes. Eur.Phys.J.ST, 155, 139-166.
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  Highly effective conversion of kinetic energy into abundant particlemultiplicity is the remarkable feature discovered in high energy heavy ioncollisions. This short and pedagogic review addresses topical issues related tothe understanding of this phenomenon, originating in the creation of thedeconfined quark--gluon plasma phase. I consider in depth the apparentlysimple, yet sometimes misunderstood, intricate issues: a) statisticalhadro-chemistry, chemical parameters, b) strange flavor chemical equilibrationin quark--gluon plasma, and c) particle yields and sudden hadronization, in thehistoric perspective of work and competition with my friend Jozsef Zimanyi.[Journal_ref: Eur.Phys.J.ST 155:139-166,2008]
• Rafelski, J. (2008). Strangeness and phase changes in hot hadronic matter-1983. EUROPEAN PHYSICAL JOURNAL A, 51(9).
• Rafelski, J. (2008). Strangeness enhancement. Challenges and successes. European Physical Journal: Special Topics, 155(1), 139-166.
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  Abstract: Highly effective conversion of kinetic energy into abundant particle multiplicity is the remarkable feature discovered in high energy heavy ion collisions. This short and pedagogic review addresses topical issues related to the understanding of this phenomenon, originating in the creation of the deconfined quark-gluon plasma phase. I consider in depth the apparently simple, yet sometimes misunderstood, intricate issues: a) statistical hadro-chemistry, chemical parameters, b) strange flavor chemical equilibration in quark-gluon plasma, and c) particle yields and sudden hadronization, in the historic perspective of work and competition with my friend József Zimányi. © EDP Sciences/Societé Italiana di Fisica/Springer-Verlag 2008.
• Rafelski, J., & Letessier, J. (2008). Particle Production and Deconfinement Threshold. PoS, CONFINEMENT8, 111.
• Rafelski, J., & Letessier, J. (2008). Particle production and deconfinement threshold. 8th Conference Quark Confinement and the Hadron Spectrum.
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  Abstract: We present a detailed analysis of the NA49 experimental particle yield results, and discuss the physical properties of the particle source. We explain in depth how our analysis differs from the work of other groups, what advance this implies in terms of our understanding, and what new physics about the deconfined particle source this allows us to recognize. We answer several frequently asked questions, presenting a transcript of a discussion regarding our data analysis. We show that the final NA49 data at 40, 80, 158 AGeV lead to a remarkably constant extensive thermal chemical-freeze-out properties of the fireball. We discuss briefly the importance of thermal hadronization pressure.
• Rafelski, J., & Letessier, J. (2008). Strangeness enhancement at LHC. J. Phys., G35, 044042.
• Rafelski, J., & Letessier, J. (2008). Strangeness enhancement at LHC. JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS, 35(4), 044042.
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  We study production of strangeness in the hot QGP fireball under conditions achieved at LHC, and use these results to obtain soft (strange) hadron multiplicities. We compare the chemical equilibrium and non-equilibrium conditions and identify characteristic experimental observables.
• Rafelski, J., & Letessier, J. (2008). Strangeness enhancement at LHC. Journal of Physics G: Nuclear and Particle Physics, 35(4).
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  Abstract: We study production of strangeness in the hot QGP fireball under conditions achieved at LHC, and use these results to obtain soft (strange) hadron multiplicities. We compare the chemical equilibrium and non-equilibrium conditions and identify characteristic experimental observables. © 2008 IOP Publishing Ltd.
• Rafelski, J., Kuznetsova, I., & Letessier, J. (2008). Strangeness and threshold of phase changes. J. Phys., G35, 044011.
• Rafelski, J., Kuznetsova, I., & Letessier, J. (2008). Strangeness at the threshold of phase change. Journal of Physics G: Nuclear and Particle Physics, 35(4).
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  Abstract: We explore entropy and strangeness as the signature of quark-gluon plasma (QGP) for the top AGS and the energy scan at SPS. We find that the hadronization dynamics changes between 20 and 30 A GeV projectile energy. The high-energy results are consistent with the QGP. © 2008 IOP Publishing Ltd.
• Torrieri, G., Jeon, S., & Rafelski, J. (2008). A statistical model analysis of yields and fluctuations in 200 GeV Au-Au collisions. NUKLEONIKA, 51, S99-S103.
• Zayakin, A. V., & Rafelski, J. (2008). Nonlocal Gluon Condensate from the Dyson--Schwinger Equations.
• Bi, P., & Rafelski, J. (2007). Delta-33 medium mass modification and pion spectra. Eur. Phys. J., A32, 267-272.
• Kuznetsova, I., & Rafelski, J. (2007). Heavy flavor hadrons in statistical hadronization of strangeness-rich QGP. EUROPEAN PHYSICAL JOURNAL C, 51(1), 113-133.
• Kuznetsova, I., & Rafelski, J. (2007). Heavy flavor hadrons in statistical hadronization of strangeness-rich QGP. Eur. Phys. J., C51, 113-133.
• Kuznetsova, I., & Rafelski, J. (2007). Heavy flavor hadrons in statistical hadronization of strangeness-rich QGP. European Physical Journal C, 51(1), 113-133.
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  Abstract: We study b and c quark hadronization from QGP. We obtain the yields of charm and bottom flavored hadrons within the statistical hadronization model. The important novel feature of this study is that we take into account the high strangeness and entropy content of QGP, conserving the strangeness and entropy yields at hadronization. © Springer-Verlag / Società Italiana di Fisica 2007.
• Letessier, J., & Rafelski, J. (2007). Strangeness chemical equilibration in QGP at RHIC and CERN LHC. Phys. Rev., C75, 014905.
• Letessier, J., & Rafelski, J. (2007). Strangeness chemical equilibration in a quark-gluon plasma. Physical Review C - Nuclear Physics, 75(1).
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  Abstract: We study, in the dynamically evolving quark-gluon plasma (QGP) fireball formed in relativistic heavy ion collisions at the BNL Relativistic Heavy Ion Collider (RHIC) and CERN Large Hadron Collider (LHC), the growth of strangeness yield toward and beyond the chemical equilibrium. We account for the contribution of the direct strangeness production and evaluate the thermal-QCD strangeness production mechanisms. The specific yield of strangeness per entropy, s/S, is the primary target variable. We explore the effect of collision impact parameter, i.e., fireball size, on kinetic strangeness chemical equilibration in QGP. Insights gained in studying the RHIC data with regard to the dynamics of the fireball are applied to the study of strangeness production at the LHC. We use these results and consider the strange hadron relative particle yields at RHIC and LHC in a systematic fashion. We consider both the dependence on s/S and the direct dependence on the participant number. © 2007 The American Physical Society.
• Pin-Zhen, B., & Rafelski, J. (2007). Δ₃₃-medium mass modification and pion spectra. European Physical Journal A, 32(3), 267-272.
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  Abstract: We study the π± spectra obtained in 2, 4, 6 and 8A GeV Au - Au collisions within the thermal model. We find that the main features of the data can be well described after we include the pions from the decay of the Δ -resonance with medium mass modification. © Società Italiana di Fisica and Springer-Verlag 2007.
• Rafelski, J. (2007). Quarks in the universe. Int.J.Mod.Phys.E, 16, 813-828.
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  Matter in its present form was formed when our Universe emerged from the quark-gluon phase (QGP) at about 30mus into itsevolution. To explore this early period in the laboratory, we study highlyexcited matter formed in relativistic heavy ion collision experiments: heavynuclei crash into each other, and form compressed and energetically excitednuclear matter, resembling in its key features the stuff which filled the earlyUniverse. In these experiments we further explore the physics of the vacuumstructure of strongly interacting gauge theory, Quantum Chromodynamics (QCD).The common beginning for both, heavy ion collisions, and vacuum structureinvestigations, is the physics of the quantum electrodynamic (QED) vacuum inthe presence of the supercritical external field that is formed when two highlycharged heavy ions are brought together near to the Coulomb barrier in aconsiderably lower reaction energy collision.[Journal_ref: Int.J.Mod.Phys.E16:813-828,2007]
• Rafelski, J. (2007). Quarks in the universe. International Journal of Modern Physics E, 16(3), 813-828.
• Torrieri, G., & Rafelski, J. (2007). Hadron Resonances and Phase Threshold in Heavy Ion Collisions. Phys. Rev., C75, 024902.
• Torrieri, G., & Rafelski, J. (2007). Hadron resonances and phase threshold in heavy ion collisions. Physical Review C - Nuclear Physics, 75(2).
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  Abstract: We show that a measurement of the reaction energy (s) dependence of relative hadron resonance yields in heavy ion collisions can be used to study the phase structure of the dense strongly interacting matter created in these collisions and investigate the origin of the trends observed in the excitation functions of certain soft hadronic observables. We show that the presence of chemical nonequilibrium in light quark abundance imparts a characteristic signature on the energy dependence of resonance yields that differs considerably from what is expected in the equilibrium picture. © 2007 The American Physical Society.
• Torrieri, G., Jeon, S., & Rafelski, J. (2007). Particle yield fluctuations and chemical nonequilibrium in Au-Au collisions at root(NN)-N-S=100 GeV. PHYSICAL REVIEW C, 74(2).
• , A. B., & , J. R. (2006). Balance of baryon number in the quark coalescence model. Phys.Lett.B, 633, 488-491.
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  The charge and baryon balance functions are studied in the coalescencehadronization mechanism of quark-gluon plasma. Assuming that in the plasmaphase the $q\bar{q}$ pairs form uncorrelated clusters whose decay is alsouncorrelated, one can understand the observed small width of the charge balancefunction in the Gaussian approximation. The coalescence model predicts evensmaller width of the baryon-antibaryon balance function:$\sigma_{B\bar{B}}/\sigma_{+-}= \sqrt{2/3}$.[Journal_ref: Phys.Lett.B633:488-491,2006]
• , J. R., & , J. L. (2006). Hadronization of Expanding QGP. Eur.Phys.J. A, 107-111.
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  We discuss how the dynamics of an exploding hot fireball of quark--gluonmatter impacts the actual phase transition conditions between the deconfinedand confined state of matter. We survey the chemical conditions prevailing athadronization.[Journal_ref: Eur.Phys.J. A29 (2006) 107-111]
• Alessandro, B., Antinori, F., Belikov, J. A., Blume, C., Dainese, A., Foka, P., Giubellino, P., Hippolyte, B., Kuhn, C., Martinez, G., Monteno, M., Morsch, A., Nayak, T. K., Nystrand, J., Noriega, M. L., Paic, G., Pluta, J., Ramello, L., Revol, J., , Safarik, K., et al. (2006). ALICE: Physics Performance Report, Volume II. JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS, 32(10), 1295-2040.
• Barish, K., Huang, H. Z., Kapusta, J., Odyniec, G., Rafelski, J., & Whitten Jr., C. A. (2006). SQM2006. Journal of Physics G: Nuclear and Particle Physics, 32(12).
• Bialas, A., & Rafelski, J. (2006). Balance of baryon number in the quark coalescence model. Phys. Lett., B633, 488-491.
• Bialas, A., & Rafelski, J. (2006). Balance of baryon number in the quark coalescence model. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 633(4-5), 488-491.
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  Abstract: The charge and baryon balance functions are studied in the coalescence hadronization mechanism of quark-gluon plasma. Assuming that in the plasma phase the qq̄ pairs form uncorrelated clusters whose decay is also uncorrelated, one can understand the observed small width of the charge balance function in the Gaussian approximation. The coalescence model predicts even smaller width of the baryon-antibaryon balance function: σBB̄/σ+-=2/3. © 2005 Elsevier B.V. All rights reserved.
• Cortese, P., Dellacasa, G., Ramello, L., Sitta, M., Ahmad, N., Ahmad, S., Ahmad, T., Bari, W., Irfan, M., Zafar, M., Botje, M., Kuijer, P. G., Snellings, R., Belogianni, A., Christakoglou, P., Ganoti, P., Petridis, A., Roukoutakis, F., Spyropoulou-Stassinaki, M., , Vassiliou, M., et al. (2006). ALICE: Physics performance report, volume II. Journal of Physics G: Nuclear and Particle Physics, 32(10).
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  Abstract: ALICE is a general-purpose heavy-ion experiment designed to study the physics of strongly interacting matter and the quark-gluon plasma in nucleus-nucleus collisions at the LHC. It currently involves more than 900 physicists and senior engineers, from both the nuclear and high-energy physics sectors, from over 90 institutions in about 30 countries. The ALICE detector is designed to cope with the highest particle multiplicities above those anticipated for Pb-Pb collisions (dNch/dy up to 8000) and it will be operational at the start-up of the LHC. In addition to heavy systems, the ALICE Collaboration will study collisions of lower-mass ions, which are a means of varying the energy density, and protons (both pp and pA), which primarily provide reference data for the nucleus-nucleus collisions. In addition, the pp data will allow for a number of genuine pp physics studies. The detailed design of the different detector systems has been laid down in a number of Technical Design Reports issued between mid-1998 and the end of 2004. The experiment is currently under construction and will be ready for data taking with both proton and heavy-ion beams at the start-up of the LHC. Since the comprehensive information on detector and physics performance was last published in the ALICE Technical Proposal in 1996, the detector, as well as simulation, reconstruction and analysis software have undergone significant development. The Physics Performance Report (PPR) provides an updated and comprehensive summary of the performance of the various ALICE subsystems, including updates to the Technical Design Reports, as appropriate. The PPR is divided into two volumes. Volume I, published in 2004 (CERN/LHCC 2003-049, ALICE Collaboration 2004 J. Phys. G: Nucl. Part. Phys. 30 1517-1763), contains in four chapters a short theoretical overview and an extensive reference list concerning the physics topics of interest to ALICE, the experimental conditions at the LHC, a short summary and update of the subsystem designs, and a description of the offline framework and Monte Carlo event generators. The present volume, Volume II, contains the majority of the information relevant to the physics performance in proton-proton, proton-nucleus, and nucleus-nucleus collisions. Following an introductory overview, Chapter 5 describes the combined detector performance and the event reconstruction procedures, based on detailed simulations of the individual subsystems. Chapter 6 describes the analysis and physics reach for a representative sample of physics observables, from global event characteristics to hard processes. © 2006 IOP Publishing Ltd.
• Fabjan, C. W., & others, . (2006). ALICE: Physics performance report, volume II. J. Phys., G32, 1295-2040.
• Kuznetsova, I., & Rafelski, J. (2006). Charmed hadrons from strangeness-rich QGP. J. Phys., G32, S499-S504.
• Kuznetsova, I., & Rafelski, J. (2006). Charmed hadrons from strangeness-rich QGP. Journal of Physics G: Nuclear and Particle Physics, 32(12).
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  Abstract: The yields of charmed hadrons emitted by strangeness-rich QGP are evaluated within the chemical non-equilibrium statistical hadronization model, conserving strangeness, charm and entropy yields at hadronization. © 2006 IOP Publishing Ltd.
• Labun, L., & Rafelski, J. (2006). Acceleration and vacuum temperature. PHYSICAL REVIEW D, 86(4).
• Labun, L., & Rafelski, J. (2006). QED energy-momentum trace as a force in astrophysics. PHYSICS LETTERS B, 687(2-3), 133-138.
• Letessier, J., & Rafelski, J. (2006). Centrality dependence of strangeness and (anti)hyperon production at RHIC. Phys. Rev., C73, 014902.
• Letessier, J., & Rafelski, J. (2006). Centrality dependence of strangeness and (anti)hyperon production at sNN=200 GeV. Physical Review C - Nuclear Physics, 73(1).
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  Abstract: We evaluate strangeness produced in Au-Au interactions at sNN=200 GeV, as a function of reaction participant number A, and obtain the relative strange quark content at hadronization. Strange baryon and antibaryon rapidity density yields are studied relative to, and as function of, participant number and produced hadron yields. © 2006 The American Physical Society.
• Petran, M., & Rafelski, J. (2006). Multistrange particle production and the statistical hadronization model. PHYSICAL REVIEW C, 82(1).
• Rafelski, J., & Letessier, J. (2006). Hadronization of expanding QGP. Eur. Phys. J., A29, 107-111.
• Rafelski, J., & Letessier, J. (2006). Hadronization of expanding QGP. European Physical Journal A, 29(1), 107-111.
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  Abstract: We discuss how the dynamics of an exploding hot fireball of quark-gluon matter impacts the actual phase transition conditions between the deconfined and confined state of matter. We survey the chemical conditions prevailing at hadronization.
• Rafelski, J., & Letessier, J. (2006). Soft hadron ratios at the LHC. Eur. Phys. J., C45, 61-72.
• Rafelski, J., & Letessier, J. (2006). Soft hadron ratios at the LHC. European Physical Journal C, 45(1), 61-72.
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  Abstract: High precision soft hadron abundance data produced in relativistic nuclear collisions at LHC at √snn ≤ 5500$ GeV will become available beginning in 2007/8. We explore, within the statistical hadronization model, how these results can help us understand the properties of the deconfined quark-gluon phase at its breakup. We make assumptions about the physical properties of the fireball and obtain particle production predictions. Then, we develop a strategy to measure parameters of interest, such as strangeness occupancy γs, chemical potentials μ B and μ S.
• Rafelski, J., & Letessier, J. (2006). Status of Strangeness-Flavor Signature of QGP. Acta Phys. Polon., B37, 3315-3342.
• Rafelski, J., & Letessier, J. (2006). Status of strangeness-flavor signature of QGP. Acta Physica Polonica B, 37(12), 3315-3341.
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  Abstract: Is the new state of matter formed in relativistic heavy ion collisions the deconfined quark-gluon plasma? We survey the status of several strange hadron observables and discuss how these measurements help understand the dense hadronic matter.
• Rafelski, J., & Letessier, J. (2006). Strangeness and the discovery of quark-gluon plasma. J. Phys. Conf. Ser., 50, 176-191.
• Rafelski, J., & Letessier, J. (2006). Strangeness and the discovery of quark-gluon plasma. Journal of Physics: Conference Series, 50, 176-191. doi:https://doi.org/10.1088/1742-6596/50/1/021
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  Abstract: Strangeness flavor yield s and the entropy yield Sare the observables of the deconfined quark-gluon state of matter which can be studied in the entire available experimental energy range at AGS, SPS, RHIC, and, in near future, at the LHC energy range. We present here a comprehensive analysis of strange, soft hadron production as function of energy and reaction volume. We discuss the physical properties of the final state and argue how evidence about the primordial QGP emerges. © 2006 IOP Publishing Ltd.
• Steinke, S., & Rafelski, J. (2006). Quantum collective QCD string dynamics. J. Phys., G32, S455-S460.
• Steinke, S., & Rafelski, J. (2006). Quantum collective QCD string dynamics. Journal of Physics G: Nuclear and Particle Physics, 32(12).
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  Abstract: The string breaking model of particle production is extended in order to help explain the transverse momentum distribution in elementary collisions. Inspired by an idea of Bialas, we treat the string using a collective coordinate approach. This leads to a chromo-electric field strength which fluctuates, and in turn implies that quarks are produced according to a thermal distribution. © 2006 IOP Publishing Ltd.
• Torrieri, G., Jeon, S., & Rafelski, J. (2006). A Statistical model analysis of yields and fluctuations in 200- GeV Au-Au collisions. Nucleonics, 51, 99-103.
• Torrieri, G., Jeon, S., & Rafelski, J. (2006). A statistical model analysis of yields and fluctuations in 200 GeV Au-Au collisions. Nukleonika, 51(SUPPL. 3), S99-S103.
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  Abstract: We show that the simultaneous measurement of yields and fluctuations is capable of falsifying and constraining the statistical hadronization model. We show how such a measurement can test for chemical non-equilibrium, and distinguish between a high temperature chemically equilibrated freeze-out from a supercooled freeze-out with an oversaturated phase space. We perform a fit, and show that both yields and fluctuations measured at RHIC 200 GeV can be accounted for within the second scenario, with both the light and strange quark phase space saturated significantly above detailed balance. We point to the simultaneous fit of the K/π fluctuation and the K*/K- ratio as evidence that the effect of hadronic re-interactions after freeze-out is small.
• Torrieri, G., Jeon, S., & Rafelski, J. (2006). Constraining freeze-out with yields and fluctuations. Rom. Rep. Phys., 58, 031-036.
• Torrieri, G., Jeon, S., & Rafelski, J. (2006). Particle multiplicities and fluctuations in 200 GeV Au-Au collisions. AIP Conference Proceedings, 828, 55-61.
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  Abstract: We use the statistical hadronization model (SHM) to describe hadron multiplicity yields and fluctuations. We consider 200 GeV Au-Au collisions, and show that both event averaged yields of stable particles and resonances, and event-by-event fluctuation of the K/π ratio can be described within the SHM using the same set of thermal parameters, provided that the phase space occupancy parameter value is significantly above chemical equilibrium, and the freeze-out temperature is ∼ 140 MeV. We present predictions that allow to test the consistency of our results. © 2006 American Institute of Physics.
• Torrieri, G., Jeon, S., & Rafelski, J. (2006). Particle multiplicities and fluctuations in 200-GeV Au-Au collisions. AIP Conf. Proc., 828, 55-61.
• Torrieri, G., Jeon, S., & Rafelski, J. (2006). Particle yield fluctuations and chemical non-equilibrium at RHIC. Phys. Rev., C74, 024901.
• Torrieri, G., Jeon, S., & Rafelski, J. (2006). Particle yield fluctuations and chemical nonequilibrium in Au-Au collisions at sNN=200 GeV. Physical Review C - Nuclear Physics, 74(2).
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  Abstract: We study charge fluctuations within the statistical hadronization model. Considering both the particle yield ratios and the charge fluctuations we show that it is possible to differentiate between chemical equilibrium and non-equilibrium freeze-out conditions. As an example of the procedure we show quantitatively how the relative yield ratio Λ/K- together with the normalized net charge fluctuation v(Q)= (ΔQ)2/Nch constrain the chemical conditions at freeze-out. We also discuss the influence of the limited detector acceptance on fluctuation measurements, and show how this can be accounted for within a quantitative analysis. © 2006 The American Physical Society.
• Torrieri, G., Jeon, S., Letessier, J., & Rafelski, J. (2006). SHAREv2: Fluctuations and a comprehensive treatment of decay feed-down. Comput. Phys. Commun., 175, 635-649.
• Torrieri, G., Jeon, S., Letessier, J., & Rafelski, J. (2006). SHAREv2: fluctuations and a comprehensive treatment of decay feed-down. COMPUTER PHYSICS COMMUNICATIONS, 175(10), 635-649.
• Torrieri, G., Jeon, S., Letessier, J., & Rafelski, J. (2006). SHAREv2: fluctuations and a comprehensive treatment of decay feed-down. Computer Physics Communications, 175(10), 635-649.
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  Abstract: This the user's manual for SHARE version 2. SHARE [G. Torrieri, S. Steinke, W. Broniowski, W. Florkowski, J. Letessier, J. Rafelski, Comput. Phys. Comm. 167 (2005) 229] (Statistical Hadronization with Resonances) is a collection of programs designed for the statistical analysis of particle production in relativistic heavy-ion collisions. While the structure of the program remains similar to v1.x, v2 provides several new features such as evaluation of statistical fluctuations of particle yields, and a greater versatility, in particular regarding decay feed-down and input/output structure. This article describes all the new features, with emphasis on statistical fluctuations. Program summary: Title of program:SHAREv2. Catalogue identifier:ADVD_v2_0. Program summary URL: http://cpc.cs.qub.ac.uk/summaries/ADVD_v2_0. Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland. Computer:PC, Pentium III, 512 MB RAM not hardware dependent. Operating system:Linux: RedHat 6.1, 7.2, FEDORA, etc. not system dependent. Programming language:FORTRAN77. Size of the package:167 KB directory, without libraries (see http://wwwasdoc.web.cern.ch/wwwasdoc/minuit/minmain.html, http://wwwasd.web.cern.ch/wwwasd/cernlib.html for details on library requirements). Number of lines in distributed program, including test data, etc.:26 101. Number of bytes in distributed program, including test data, etc.:170 346. Distribution format:tar.gzip file. Computer:Any computer with an f77 compiler. Nature of the physical problem:Event-by-event fluctuations have been recognized to be the physical observable capable to constrain particle production models. Therefore, consideration of event-by-event fluctuations is required for a decisive falsification or constraining of (variants of) particle production models based on (grand-, micro-) canonical statistical mechanics phase space, the so called statistical hadronization models (SHM). As in the case of particle yields, to properly compare model calculations to data it is necessary to consistently take into account resonance decays. However, event-by-event fluctuations are more sensitive than particle yields to experimental acceptance issues, and a range of techniques needs to be implemented to extract 'physical' fluctuations from an experimental event-by-event measurement. Method of solving the problem:The techniques used within the SHARE suite of programs [G. Torrieri, S. Steinke, W. Broniowski, W. Florkowski, J. Letessier, J. Rafelski, Comput. Phys. Comm. 167 (2005) 229; SHAREv1] are updated and extended to fluctuations. A full particle data-table, decay tree, and set of experimental feed-down coefficients are provided. Unlike SHAREv1.x, experimental acceptance feed-down coefficients can be entered for any resonance decay. SHAREv2 can calculate yields, fluctuations, and bulk properties of the fireball from provided thermal parameters; alternatively, parameters can be obtained from fits to experimental data, via the MINUIT fitting algorithm [F. James, M. Roos, Comput. Phys. Comm. 10 (1975) 343]. Fits can also be analyzed for significance, parameter and data point sensitivity. Averages and fluctuations at freeze-out of both the stable particles and the hadronic resonances are set according to a statistical prescription, calculated via a series of Bessel functions, using CERN library programs. We also have the option of including finite particle widths of the resonances. A χ2 minimization algorithm, also from the CERN library programs, is used to perform and analyze the fit. Please see SHAREv1 for more details on these. Purpose:The vast amount of high quality soft hadron production data, from experiments running at the SPS, RHIC, in past at the AGS, and in the near future at the LHC, offers the opportunity for statistical particle production model falsification. This task has turned out to be difficult when considering solely particle yields addressed in the context of SHAREv1.x. For this reason physical conditions at freeze-out remain contested. Inclusion in the analysis of event-by-event fluctuations appears to resolve this issue. Similarly, a thorough analysis including both fluctuations and average multiplicities gives a way to explore the presence and strength of interactions following hadronization (when hadrons form), ending with thermal freeze-out (when all interactions cease). SHAREv2 with fluctuations will also help determine which statistical ensemble (if any), e.g., canonical or grand-canonical, is more physically appropriate for analyzing a given system. Together with resonances, fluctuations can also be used for a direct estimate of the extent the system re-interacts between chemical and thermal freeze-out. We hope and expect that SHAREv2 will contribute to decide if any of the statistical hadronization model variants has a genuine physical connection to hadron particle production. Computation time survey:We encounter, in the FORTRAN version computation, times up to seconds for evaluation of particle yields. These rise by up to a factor of 300 in the process of minimization and a further factor of a few when χ2 / NDoF profiles and contours with chemical non-equilibrium are requested. Summary of new features (w.r.t. SHAREv1.x): Fluctuations:In addition to particle yields, ratios and bulk quantities SHAREv2 can calculate, fit and analyze statistical fluctuations of particles and particle ratios. Decays:SHAREv2 has the flexibility to account for any experimental method of allowing for decay feed-downs to the particle yields. Charm flavor:Charmed particles have been added to the decay tree, allowing as an option study of statistical hadronization of J / ψ, χc, Dc, etc. Quark chemistry:Chemical non-equilibrium yields for both u and d flavors, as opposed to generically light quarks q, are considered; η-η′ mixing, etc., are properly dealt with, and chemical non-equilibrium can be studied for each flavor separately. Misc:Many new commands and features have been introduced and added to the basic user interface. For example, it is possible to study combinations of particles and their ratios. It is also possible to combine all the input files into one file. SHARE compatibility and manual:This write-up is an update and extension of SHAREv1. The user should consult SHAREv1 regarding the principles of user interface and for all particle yield related physics and program instructions, other than the parameter additions and minor changes described here. SHAREv2 is downward compatible for the changes of the user interface, offering the user of SHAREv1 a computer generated revised input files compatible with SHAREv2. © 2006 Elsevier B.V. All rights reserved.
• , G. T., & , J. R. (2005). Multiplicities and bulk thermodynamic quantities at \mathversion{bold}{$\sqrt{s_{NN}}=130$} GeV with SHARE. J.Phys.Conf.Ser..
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  We introduce the Statistical Hadronization with Resonances (SHARE) suite ofprograms and perform a study of particle multiplicities as well as bulkthermodynamic quantities for the RHIC Au--Au reactions at $\sqrt{s_{NN}}=130$GeV. We also show that the statistical hadronization model, with parametersfitted to match pion, proton and hyperon ratios, in turn correctly andconsistently reproduces rapidity particle multiplicity.[Journal_ref: J.Phys.Conf.Ser. 5 (2005) 246]
• Huang, H. Z., & Rafelski, J. (2005). Hadronization and quark probes of deconfinement at RHIC. AIP Conf. Proc., 756, 210-227.
• Huang, H. Z., & Rafelski, J. (2005). Hadronization and quark probes of deconfinement at RHIC. AIP Conference Proceedings, 756, 210-227.
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  Abstract: We discuss experimental features of identified particle production from nucleus-nucleus collisions. These features reflect hadronization from a deconfined partonic matter whose particle formation scheme is distinctly different from fragmentation phenomenology in elementary collisions. Multi-parton dynamics, such as quark coalescences or recombinations, appear to be essential to explain the experimental measurements at the intermediate transverse momentum of 2-5 GeV/c. Constituent quarks seem to be the dominant degrees of freedom at hadronization. Heavy quark production should help quantify deconfined matter properties. © 2005 American Institute of Physics.
• Rafelski, J., Letessier, J., & Torrieri, G. (2005). Centrality dependence of bulk fireball properties at RHIC. Phys. Rev., C72, 024905.
• Rafelski, J., Letessier, J., & Torrieri, G. (2005). Centrality dependence of bulk fireball properties in root s(NN)=200 GeVAu-Au collisions. PHYSICAL REVIEW C, 72(2).
• Rafelski, J., Letessier, J., & Torrieri, G. (2005). Centrality dependence of bulk fireball properties in sNN=200GeV Au-Au collisions. Physical Review C - Nuclear Physics, 72(2).
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  Abstract: We explore the centrality dependence of the properties of the dense hadronic matter created in sNN=200 GeV Au-Au collisions at the Relativistic Heavy Ion Collider. Using the statistical hadronization model, we fit particle yields known for 11 centrality bins. We present the resulting model parameters, rapidity yields of physical quantities, and the physical properties of bulk matter at hadronization as function of centrality. We discuss the production of strangeness and entropy. © 2005 The American Physical Society.
• Torrieri, G., & Rafelski, J. (2005). Multiplicities and bulk thermodynamic quantities at s(NN)**(1/2) = 130-GeV with SHARE. J. Phys. Conf. Ser., 5, 246.
• Torrieri, G., Steinke, S., Broniowski, W., Florkowski, W., Letessier, J., & Rafelski, J. (2005). SHARE: Statistical hadronization with resonances. COMPUTER PHYSICS COMMUNICATIONS, 167(3), 229-251.
• Torrieri, G., Steinke, S., Broniowski, W., Florkowski, W., Letessier, J., & Rafelski, J. (2005). SHARE: Statistical hadronization with resonances. Comput. Phys. Commun., 167, 229-251.
• Torrieri, G., Steinke, S., Broniowski, W., Florkowski, W., Letessier, J., & Rafelski, J. (2005). SHARE: Statistical hadronization with resonances. Computer Physics Communications, 167(3), 229-251.
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  Abstract: SHARE is a collection of programs designed for the statistical analysis of particle production in relativistic heavy-ion collisions. With the physical input of intensive statistical parameters, it generates the ratios of particle abundances. The program includes cascade decays of all confirmed resonances from the Particle Data Tables. The complete treatment of these resonances has been known to be a crucial factor behind the success of the statistical approach. An optional feature implemented is the Breit-Wigner distribution for strong resonances. An interface for fitting the parameters of the model to the experimental data is provided.
• , J. R., & , J. L. (2004). Strangeness and Quark Gluon Plasma. J.Phys.G, 30.
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  A brief summary of strangeness mile stones is followed by a chemicalnon-equilibrium statistical hadronization analysis of strangeness results atSPS and RHIC. Strange particle production in AA interactions at\sqrt{s_{NN}}\ge 8.6 GeV can be understood consistently as originating from thedeconfined quark--gluon plasma in a sudden hadronization process. Onset of QGPformation as function of energy is placed in the beam energy interval 10--30AGeV/c. Strangeness anomalies at LHC are described.[Journal_ref: J.Phys.G30:S1-S28,2004]
• , T. J., & , J. R. (2004). Generalization of Boltzmann Equilibration Dynamics. Lect.NotesPhys., 633, 377-384.
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  We propose a novel approach in the study of transport phenomena in densesystems or systems with long range interactions where multiple particleinteractions must be taken into consideration. Within Boltzmann's kineticformalism, we study the influence of other interacting particles in terms of arandom distortion of energy and momentum conservation occurring whenmulti-particle interactions are considered as binary collisions. Energy andmomentum conservation still holds exactly but not in each model binarycollision. We show how this new system differs from the Boltzmann system and wenote that our approach naturally explains the emergence of Tsallis-likeequilibrium statistics in physically relevant systems in terms of the longsince neglected physics of interacting and dense systems.[Journal_ref: Lect.NotesPhys.633:377-384,2004]
• Letessier, J., Rafelski, J., & Torrieri, G. (2004). Deconfinement energy threshold: Analysis of hadron yields at 11.6-A GeV.
• Rafelski, J., & Letessier, J. (2004). Strangeness and quark gluon plasma. J. Phys., G30, S1-S28.
• Rafelski, J., & Letessier, J. (2004). Strangeness and quark-gluon plasma. Journal of Physics G: Nuclear and Particle Physics, 30(1), S1-S28.
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  Abstract: A brief summary of strangeness milestones is followed by a chemical nonequilibrium statistical hadronization analysis of strangeness results at SPS and RHIC. Strange particle production in A A interactions at √S NN ≥ 8.6 GeV can be understood consistently as originating from the deconfmed quark-gluon plasma (QGP) in a sudden hadronization process. Onset of QGP formation as function of energy is placed in the beam energy interval 10-30 A GeV/c. Strangeness anomalies at LHC are described.
• Rafelski, J., & Letessier, J. (2004). Strangeness excitation function in heavy ion collisions. AIP Conf. Proc., 739, 216-222.
• Sherman, T. J., & Rafelski, J. (2004). Generalization of Boltzmann equilibration dynamics. Lect. Notes Phys., 633, 377-384.
• Torrieri, G., & Rafelski, J. (2004). A Comparison of statistical hadronization models. J. Phys., G30, S557-S564.
• Torrieri, G., & Rafelski, J. (2004). A comparison of statistical hadronization models. Journal of Physics G: Nuclear and Particle Physics, 30(1), S557-S564.
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  Abstract: We investigate the sensitivity of fits of hadron spectra produced in heavy-ion collisions to the choice of statistical hadronization model. We start by giving an overview of statistical model ambiguities, and what they tell us about freeze-out dynamics. We then use Monte Carlo generated data to determine sensitivity to model choice. We fit the statistical hadronization models under consideration to RHIC data, and find that a comparison χ2 fits can shed light on some presently contentious questions.
• Torrieri, G., & Rafelski, J. (2004). Hadron resonance probes of QGP. Nukleonika, 49(SUPPL.2), S109-S114.
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  Abstract: We discuss the indirect and direct role of the short-lived resonances as probes of QGP freeze-out process. The indirect effect is the distortion of stable single particle yields and spectra by contributions of decaying resonances, which alter significantly the parameters obtained in fits to experimental data. We then discuss the direct observation of short-lived resonances as a probe of post-hadronization dynamics allowing to distinguish between different hadronization models.
• Torrieri, G., & Rafelski, J. (2004). Hadron resonance probes of QGP. Nukleonika, 49(suppl.2), s109-s114.
• Torrieri, G., Letessier, J., Rafelski, J., & Steinke, S. (2004). Statistical hadronization with resonances. Acta Phys. Polon., B35, 2911-2927.
• Torrieri, G., Letessier, J., Rafelski, J., & Steinke, S. (2004). Statistical hadronization with resonances. Acta Physica Polonica B, 35(12), 2911-2927.
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  Abstract: We introduce the equilibrium and non-equilibrium statistical hadronization picture of particle production in ultra-relativistic heavy ion collisions. We describe the related physical reaction scenarios, and show how these can lead to quark pair yield non-equilibrium. Using the SHARE1.2 program suite we quantitatively model particle yields and ratios for RHIC-130 run. We study how experimental particle ratios can differentiate between model scenarios, and discuss in depth the importance of hadronic resonances in understanding of hadron production processes.
• , J. L., & , J. R. (2003). QCD Equations of State and the QGP Liquid Model. Phys.Rev. C.
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  Recent advances in the study of equations of state of thermal lattice QuantumChromodynamics obtained at non-zero baryon density allow validation of thequark-gluon plasma (QGP) liquid model equations of state (EoS). We study herethe properties of the QGP-EoS near to the phase transformation boundary atfinite baryon density and show a close agreement with the lattice results.[Journal_ref: Phys.Rev. C67 (2003) 031902]
• Fromerth, M. J., & Rafelski, J. (2003). Limit of quark-antiquark mass difference from the neutral kaon system. Acta Physica Polonica B, 34(8), 4151-4155.
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  Abstract: We quantify the limits on quark-antiquark mass differences imposed by the neutral kaon mass system. In particular, we find that an upper limit to the mass difference of 10-3 eV exists if mass differences across quark flavors are uncorrelated. In the upcoming antihydrogen experiments this limit on quark mass difference would allow a measurement of electron-positron mass difference up to a relative precision level of 10-15.
• Fromerth, M. J., & Rafelski, J. (2003). Limit on CPT violating quark anti-quark mass difference from the neutral kaon system. Acta Phys. Polon., B34, 4151-4156.
• Letessier, J., & Rafelski, J. (2003). QCD equations of state and the QGP liquid model. Phys. Rev., C67, 031902.
• Letessier, J., & Rafelski, J. (2003). QCD equations of state and the quark-gluon plasma liquid model. PHYSICAL REVIEW C, 67(3).
• Letessier, J., & Rafelski, J. (2003). QCD equations of state and the quark-gluon plasma liquid model. Physical Review C - Nuclear Physics, 67(3), 319021-319024.
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  Abstract: Recent advances in the study of equations of state of thermal lattice quantum chromodynamics obtained at nonzero baryon density allow validation of the quark-gluon plasma (QGP) liquid model equations of state (EOS). We study here the properties of the QGP-EOS near to the phase transformation boundary at finite baryon density and show a close agreement with the lattice results.
• Letessier, J., Torrieri, G., Steinke, S., & Rafelski, J. (2003). Strange pentaquark hadrons in statistical hadronization. PHYSICAL REVIEW C, 68(6).
• Letessier, J., Torrieri, G., Steinke, S., & Rafelski, J. (2003). Strange pentaquark hadrons in statistical hadronization. Phys. Rev., C68, 061901.
• Letessier, J., Torrieri, G., Steinke, S., & Rafelski, J. (2003). Strange pentaquark hadrons in statistical hadronization. Physical Review C - Nuclear Physics, 68(6), 619011-619014.
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  Abstract: We study, within the statistical hadronization model, the influence of narrow strangeness carrying baryon resonances (pentaquarks) on the understanding of particle production in relativistic heavy ion collisions. There is a great variation of expected yields as a function of heavy ion collision energy due to rapidly evolving chemical conditions at particle chemical freeze-out. At relatively low collision energies, these new states lead to improvement of statistical hadronization fits.
• Rafelski, J., & Ericson, T. (2003). The tale of the Hagedorn temperature. CERN Cour., 43N7, 30-33.
• Rafelski, J., & Letessier, J. (2003). Strangeness and statistical hadronization: How to study quark gluon plasma. Acta Phys. Polon., B34, 5791-5824.
• Rafelski, J., & Letessier, J. (2003). Strangeness and statistical hadronization: How to study quark-gluon plasma. Acta Physica Polonica B, 34(12), 5791-5823.
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  Abstract: Statistical hadronization is presented as mechanism for (strange) particle production from a deconfined quark-gluon plasma (QGP) fireball. We first consider hadronic resonance production at RHIC as a test of the model. We present in detail how the hadrochemistry determines particle multiplicitties and in case of sudden hadronization allows investigation of QGP properties. A comparative study of strange hadron production at SPS and RHIC is presented. The energy dependence of physical observables shows regularities and a potential discontinuity in the low RHIC range, when comparing these different energy domains. Considering the energy scan program at CERN-SPS we show that the K+/π+ discontinuity is a baryon density effect.
• Rafelski, J., & Letessier, J. (2003). Testing limits of statistical hadronization. NUCLEAR PHYSICS A, 715, 98C-107C.
• Rafelski, J., & Letessier, J. (2003). Testing limits of statistical hadronization. Nucl. Phys., A715, 98-107.
• Rafelski, J., & Letessier, J. (2003). Testing limits of statistical hadronization. Nuclear Physics A, 715, 98c-107c.
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  Abstract: Much of the energy of the nuclei colliding at RHIC or SPS is converted into final state hadronic particles. About a quarter of this energy is in baryons and antibaryons. There are nearly 10 strange quark pairs per central rapidity participant. Do we really understand the hadronic particle yields? Do we need to introduce post-Fermi-model ideas such as chemical non-equilibrium in order to understand how a deconfined state hadronizes? © 2003 Elsevier Science B.V. All rights reserved.
• Torrieri, G., & Rafelski, J. (2003). Statistical hadronization probed by resonances. Phys. Rev., C68, 034912.
• Torrieri, G., & Rafelski, J. (2003). Statistical hadronization probed by resonances. Physical Review C - Nuclear Physics, 68(3), 349121-3491210.
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  Abstract: We study to what extent a measurement of the m⊥ spectra for hadrons and their resonances can resolve ambiguities in the statistical model description of particle production. We describe in a quantitative analysis how physical assumptions about the freeze-out geometry and dynamics influence the particle spectra. Considering ratios of m⊥ distribution of resonance-particle ratios (such as K*/K, Σ*/λ, η′/η) we observe significant sensitivity to fireball freeze-out geometry and flow dynamics.
• Fromerth, M. J., & Rafelski, J. (2002). Hadronization of the quark Universe.
• Letessier, J., & Rafelski, J. (2002). Rapidity particle spectra in sudden hadronization of QGP. J. Phys., G28, 183-188.
• Letessier, J., & Rafelski, J. (2002). Rapidity particle spectra in sudden hadronization of QGP. Journal of Physics G: Nuclear and Particle Physics, 28(1), 183-187.
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  Abstract: We show that the remaining internal longitudinal flow of colliding quarks in nuclei offers a natural explanation for the diversity of rapidity spectral shapes observed in Pb-Pb 158A GeV nuclear collisions. Thus QGP sudden hadronization reaction picture is a suitable approach to explain the rapidity spectra of hadrons produced.
• Markert, C., Torrieri, G., & Rafelski, J. (2002). Strange Hadron Resonances: Freeze‐Out Probes in Heavy‐Ion Collisions. AIP Conf. Proc., 631, 533-552.
• Rafelski, J. (2002). Strangeness, equilibration, hadronization. Journal of Physics G: Nuclear and Particle Physics, 28(7), 1833-1840. doi:https://doi.org/10.1088/0954-3899/28/7/337
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  In these remarks I explain the motivation which leads us to consider chemical non-equilibrium processes in flavour equilibration and in statistical hadroniziation of quark-gluon plasma (QGP). Statistical hadronization allowing for chemical non-equilibrium is introduced. The results of fits to RHIC-130 results, including multistrange hadrons, are shown to agree only with the model of an exploding QGP fireball.
• Rafelski, J. (2002). Variation of fine structure constant from nonuniversal gravity.
• Rafelski, J. -., Rafelski, J., McGuire, P. C., Bohr, H., Clark, J. W., Haschke, R., & Pershing, C. L. (2002). Threshold disorder as a source of diverse and complex behavior in random nets. Neural networks : the official journal of the International Neural Network Society, 15(10).
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  We study the diversity of complex spatio-temporal patterns in the behavior of random synchronous asymmetric neural networks (RSANNs). Special attention is given to the impact of disordered threshold values on limit-cycle diversity and limit-cycle complexity in RSANNs which have 'normal' thresholds by default. Surprisingly, RSANNs exhibit only a small repertoire of rather complex limit-cycle patterns when all parameters are fixed. This repertoire of complex patterns is also rather stable with respect to small parameter changes. These two unexpected results may generalize to the study of other complex systems. In order to reach beyond this seemingly disabling 'stable and small' aspect of the limit-cycle repertoire of RSANNs, we have found that if an RSANN has threshold disorder above a critical level, then there is a rapid increase of the size of the repertoire of patterns. The repertoire size initially follows a power-law function of the magnitude of the threshold disorder. As the disorder increases further, the limit-cycle patterns themselves become simpler until at a second critical level most of the limit cycles become simple fixed points. Nonetheless, for moderate changes in the threshold parameters, RSANNs are found to display specific features of behavior desired for rapidly responding processing systems: accessibility to a large set of complex patterns.
• Rafelski, J., & Letessier, J. (2002). Importance of reaction volume in hadronic collisions: Canonical enhancement. J. Phys., G28, 1819-1832.
• Rafelski, J., & Letessier, J. (2002). Importance of reaction volume in hadronic collisions: Canonical enhancement. Journal of Physics G: Nuclear and Particle Physics, 28(7), 1819-1832.
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  Abstract: We study the canonical flavour enhancement arising from exact conservation of strangeness and charm flavour. Both the theoretical motivation, and the practical consequences are explored. We argue using qualitative theoretical arguments and quantitative evaluation, that this proposal to re-evaluate strangeness signature of quark-gluon plasma is not able to explain the majority of available experimental results.
• Rafelski, J., & Letessier, J. (2002). Non‐equilibrium Hadrochemistry in QGP Hadronization. AIP Conf. Proc., 631, 460-489.
• Rafelski, J., & Letessier, J. (2002). Quark‐Gluon Plasma, and Strangeness. AIP Conf. Proc., 631, 142-167.
• Rafelski, J., & Letessier, J. (2002). Strangeness and statistical QCD. Nucl. Phys., A702, 304-325.
• Rafelski, J., & Letessier, J. (2002). Strangeness and statistical QCD. Nuclear Physics A, 702(1-4), 304c-325c.
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  Abstract: We discuss properties of statistical QCD relevant in Fermi phase space model analysis of hadron production experimental data. We argue that the analysis results interpreted using established statistical QCD properties are demonstrating formation of the color deconfined state of matter in relativistic heavy ion collisions at highest CERN-SPS energies and at BNL-RHIC, comprising deconfined matter composed of nearly massless quarks and gluons, in statistical equilibrium.
• Rafelski, J., Letessier, J., & Torrieri, G. (2002). Erratum: Strange hadrons and their resonances: A diagnostic tool of quark-gluon plasma freeze-out dynamics (Physical Review C (2001) 64 (054907)). Physical Review C - Nuclear Physics, 65(6), 699021-.
• Thews, R. L., & Rafelski, J. (2002). J/Psi production at RHIC in a QGP. Nuclear Physics A, 698(1-4), 575c-578c.
• Torrieri, G., & Rafelski, J. (2002). Strange hadron resonances and QGP freeze-out. JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS, 28(7), 1911-1919.
• Torrieri, G., & Rafelski, J. (2002). Strange hadron resonances and QGP freeze-out. Journal of Physics G: Nuclear and Particle Physics, 28(7), 1911-1919.
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  Abstract: We describe how the abundance and distribution of hyperon resonances can be used to probe freeze-out conditions. We demonstrate that resonance yields allow us to measure the time scales of chemical and thermal freeze-outs. This should permit a direct differentiation between the explosive, sudden and staged adiabatic freeze-out scenarios. We then discuss the meaning of recent experimental results and suggest further measurements.
• Torrieri, G., & Rafelski, J. (2002). Strange hadron resonances and QGP freezeout. J. Phys., G28, 1911-1920.
• , G. T., & , J. R. (2001). Strange hadron resonances as a signature of freeze-out dynamics. Phys.Lett. B, 239-245.
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  We study the production and the observability of Lambda*(1520), K*0(892), andSigma*(1385), strange hadron resonances as function of the freeze-outconditions within the statistical model of hadron production. We obtain anestimate of how many decay products are rescattered in evolution towardsthermal freeze-out following chemical freeze-out, and find that the resonancedecay signal is strong enough to be detected. We show how a combined analysisof at least two resonances can be used to understand the chemical freeze-outtemperature, and the time between chemical and thermal freeze-outs.[Journal_ref: Phys.Lett. B509 (2001) 239-245]
• Danos, M., & Rafelski, J. (2001). Baryon-Rich Quark-Gluon Plasma in Nuclear Collisions. Acta Physica Hungarica New Series Heavy Ion Physics, 14(1-4), 97-120.
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  Abstract: The maximum achievable temperature (energy density) and minimum kinetic energy required for the formation of a baryon-rich quark-gluon plasma formed at central rapidity in small impact parameter nuclear collisions is estimated. A possible mechanism leading to the pile-up of matter is introduced. Plasma formation is expected to appear at about 15 GeV/Nucleon uranium beam energy on a stationary target or 2.7 GeV/Nucleon in colliding beams.
• Elze, H. T., Rafelski, J., & Turko, L. (2001). Entropy production in relativistic hydrodynamics. PHYSICS LETTERS B, 506(1-2), 123-130.
• Elze, H. T., Rafelski, J., & Turko, L. (2001). Entropy production in relativistic hydrodynamics. Phys. Lett., B506, 123-130.
• Elze, H., Rafelski, J., & Turko, L. (2001). Entropy production in relativistic hydrodynamics. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 506(1-2), 123-130.
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  Abstract: The entropy production occurring in relativistic hydrodynamical systems such as the quark - gluon plasma (QGP) formed in high-energy nuclear collisions is explored. We study mechanisms which change the composition of the fluid, i.e., particle production and/or chemical reactions, along with chemo- and thermo-diffusion. These effects complement the conventional dissipative effects of shear viscosity, bulk viscosity, and heat conductivity. © 2001 Elsevier Science B.V.
• Fatuzzo, M., Melia, F., & Rafelski, J. (2001). Electron-positron annihilation radiation from sagittarius a east at the galactic center. Astrophysical Journal Letters, 549(1 PART 1), 293-302.
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  Abstract: Maps of the Galactic electron-positron annihilation radiation show evidence for three distinct and significant features: (1) a central bulge source, (2) emission in the Galactic plane, and (3) an enhancement of emission at positive latitudes above the Galactic center. In this paper, we explore the possibility that Sgr A East, a very prominent radio structure surrounding the Galactic nucleus, may be a significant contributor to the central bulge feature. The motivation for doing so stems from a recently proposed link between this radio object and the EGRET γ-ray source 2EG J1746-2852. If this association is correct, then Sgr A East is also expected to be a source of copious positron production. The results presented here show that indeed Sgr A East must have produced a numerically significant population of positrons, but also that most of them have not yet had sufficient time to thermalize and annihilate. As such, Sgr A East by itself does not appear to be the dominant current source of annihilation radiation, but it will be when the positrons have cooled sufficiently and they have become thermalized. This raises the interesting possibility that the bulge component may be a result of the relics of earlier explosive events like the one that produced Sgr A East.
• Letessier, J., Torrieri, G., Hamieh, S., & Rafelski, J. (2001). Quark-gluon plasma fireball explosion. Journal of Physics G: Nuclear and Particle Physics, 27(3), 427-437.
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  Abstract: We identify the major physics milestones in the development of strange hadrons as an observable for both the formation of a quark-gluon plasma (QGP), and of the ensuing explosive disintegration of a deconfined matter fireball formed in relativistic heavy-ion collisions at 160-20 A GeV. We describe the physical properties of the QGP phase and show agreement with the expectations based on an analysis of hadron abundances. We then also demonstrate that the m⊥ shape of hadron spectra is in qualitative agreement with the sudden breakup of a supercooled QGP fireball.
• Rafelski, J. (2001). On the strange-quark-gluon plasma front line. J. Phys., G27, 723-726.
• Rafelski, J. (2001). On the strange-quark-gluon plasma front line. Journal of Physics G: Nuclear and Particle Physics, 27(3), 723-726.
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  Abstract: The issue for me here is why has everybody been so quiet at this 'Strangeness in Quark Matter' meeting about the most significant recent event in our field, which is the CERN announcement of February 2000. Let me try to answer this question.
• Rafelski, J., Letessier, J., & Torrieri, G. (2001). Strange hadrons and their resonances: A Diagnostic tool of QGP freezeout dynamics. Phys. Rev., C64, 054907.
• Rafelski, J., Letessier, J., & Torrieri, G. (2001). Strange hadrons and their resonances: A diagnostic tool of quark-gluon plasma freeze-out dynamics. PHYSICAL REVIEW C, 64(5).
• Rafelski, J., Letessier, J., & Torrieri, G. (2001). Strange hadrons and their resonances: A diagnostic tool of quark-gluon plasma freeze-out dynamics. Physical Review C - Nuclear Physics, 64(5), 549071-549077.
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  Abstract: We update our chemical analysis of (strange) hadrons produced at the SPS in Pb-Pb collisions at 158A GeV and discuss chemical analysis of RHIC results. We report that the shape of (anti)hyperon m⊥ spectra in a thermal freeze-out analysis leads to freeze-out conditions found in chemical analysis, implying sudden strange-hyperon production. We discuss how a combined analysis of several strange-hadron resonances of differing lifespan can be used to understand the dynamical process present during chemical and thermal freeze-outs. In medium resonance quenching is considered.
• Schroedter, M., Thews, R. L., & Rafelski, J. (2001). Charm production in the hot-glue scenario. J. Phys., G27, 691-694.
• Schroedter, M., Thews, R. L., & Rafelski, J. (2001). Charm production in the hot-glue scenario. Journal of Physics G: Nuclear and Particle Physics, 27(3), 691-694.
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  Abstract: Charm production by gluons and light quarks not in chemical equilibrium (the hot-glue scenario) is explored in a one-dimensional Bjorken-type expansion. The quark-gluon plasma background evolves according to chemical kinetic equations that include gluon fragmentation and light quark production. The momentum distributions of all particles are assumed to be Bose/Fermi. The parameter space is constrained through the initial energy density and the final state entropy. It is found that initial hard processes contribute far more to the final state charm abundance than in plasma production.
• Thews, R. L., Schroedter, M., & Rafelski, J. (2001). Enhanced J/psi production in deconfined quark matter. PHYSICAL REVIEW C, 63(5).
• Thews, R. L., Schroedter, M., & Rafelski, J. (2001). Enhanced J/ψ production in deconfined quark matter. Physical Review C - Nuclear Physics, 63(5), 549051-549055.
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  Abstract: In high energy heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven and the Large Hadron Collider at CERN, each central event will contain multiple pairs of heavy quarks. If a region of deconfined quarks and gluons is formed, a mechanism for additional formation of heavy quarkonium bound states will be activated. This is a result of the mobility of heavy quarks in the deconfined region, such that bound states can be formed from a quark and an antiquark that were originally produced in separate incoherent interactions. Model estimates of this effect for J/ψ production at RHIC indicate that significant enhancements are to be expected. Experimental observation of such enhanced production would provide evidence for deconfinement unlikely to be compatible with competing scenarios.
• Thews, R. L., Schroedter, M., & Rafelski, J. (2001). Formation of quarkonium states at RHIC. Journal of Physics G: Nuclear and Particle Physics, 27(3), 715-722.
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  Abstract: At RHIC the cross section for cc production will be large enough such that approximately ten pairs will be produced in each central collision. If a region of deconfined quarks and gluons is subsequently formed, one would expect that the mobility of the charm quarks will enable them to form J/ψ through 'off-diagonal' combinations, involving a quark and an antiquark which were originally produced in separate incoherent interactions. We present model estimates of this effect, which indicate that the signal for deconfinement at RHIC may possibly be J/ψ enhancement rather than suppression.
• Torrieri, G., & Rafelski, J. (2001). Search for QGP and thermal freeze-out of strange hadrons. NEW JOURNAL OF PHYSICS, 3, 121-1217.
• Torrieri, G., & Rafelski, J. (2001). Search for QGP and thermal freeze-out of strange hadrons. New Journal of Physics, 3, 12.1-12.17.
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  Abstract: After reviewing the observables of QGP we perform an analysis of m⊥ spectra of strange hadrons measured as function of centrality in 156 A GeV Pb-Pb interactions. We show that there is a good agreement between the chemical and thermal freeze-out conditions, providing additional evidence for the formation and sudden disintegration of a supercooled QGP fireball.
• Torrieri, G., & Rafelski, J. (2001). Strange hadron resonances as a signature of freeze-out dynamics. PHYSICS LETTERS B, 509(3-4), 239-245.
• Torrieri, G., & Rafelski, J. (2001). Strange hadron resonances as a signature of freeze-out dynamics. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 509(3-4), 239-245.
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  Abstract: We study the production and the observability of Λ*(1520), Κ*0(892), and Σ*(1385), strange hadron resonances as function of the freeze-out conditions within the statistical model of hadron production. We obtain an estimate of how many decay products are rescattered in evolution towards thermal freeze-out following chemical freeze-out, and find that the resonance decay signal is strong enough to be detected. We show how a combined analysis of at least two resonances can be used to understand the chemical freeze-out temperature, and the time between chemical and thermal freeze-outs. © 2001 Elsevier Science B.V.
• Torrieri, G., & Rafelski, J. (2001). Strange hadron resonances as a signature of freezeout dynamics. Phys. Lett., B509, 239-245.
• Turko, L., & Rafelski, J. (2001). Dynamics of multiparticle systems with non-abelian symmetry. European Physical Journal C, 18(3), 587-592.
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  Abstract: We consider the dynamics governing the evolution of a many body system constrained by a nonabelian local symmetry. We obtain explicit forms of the global macroscopic condition assuring that at the microscopic level the evolution respects the overall symmetry constraint. We demonstrate the constraint mechanisms for the case of SU (2) system comprising particles in fundamental, and adjoint representations ('nucleons' and 'pions').
• , D. B., & , J. R. (2000). Equilibrium Distribution of Heavy Quarks in Fokker-Planck Dynamics. Phys.Rev.Lett., 31-34.
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  We obtain within Fokker-Planck dynamics an explicit generalization ofEinstein's relation between drag, diffusion and equilibrium distribution for aspatially homogeneous system, considering both the transverse and longitudinaldiffusion for dimension n>1. We then provide a complete characterization ofwhen the equilibrium distribution becomes a Boltzmann/J"uttner distribution,and when it satisfies the more general Tsallis distribution. We apply thisanalysis to recent calculations of drag and diffusion of a charm quark in athermal plasma, and show that only a Tsallis distribution describes theequilibrium distribution well. We also provide a practical recipe applicable tohighly relativistic plasmas, for determining both diffusion coefficients sothat a specific equilibrium distribution will arise for a given dragcoefficient.[Journal_ref: Phys.Rev.Lett. 84 (2000) 31-34]
• , J. L., & , J. R. (2000). Observing Quark-Gluon Plasma with Strange Hadrons. Int.J.Mod.Phys.E, 107-147.
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  We review the methods and results obtained in an analysis of the experimentalheavy ion collision research program at nuclear beam energy of 160-200A GeV. Westudy strange, and more generally, hadronic particle production experimentaldata. We discuss present expectations concerning how these observables willperform at other collision energies. We also present the dynamical theory ofstrangeness production and apply it to show that it agrees with availableexperimental results. We describe strange hadron production from thebaryon-poor quark-gluon phase formed at much higher reaction energies, wherethe abundance of strange baryons and antibaryons exceeds that of nonstrangebaryons and antibaryons.[Journal_ref: Int.J.Mod.Phys.E9:107-147,2000]
• , J. R., & , J. L. (2000). Sudden Hadronization in Relativistic Nuclear Collisions. Phys.Rev.Lett., 4695-4698.
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  We formulate and study a mechanical instability criterion for suddenhadronization of dense matter fireballs formed in 158A GeV Pb--Pb collisions.Considering properties of quark-gluon matter and hadron gas we obtain the phaseboundary between these two phases and demonstrate that the required deep QGPsupercooling prior to sudden hadronization has occurred.[Journal_ref: Phys.Rev.Lett. 85 (2000) 4695-4698]
• Hamieh, S., Letessier, J., & Rafelski, J. (2000). Quark-gluon plasma fireball. Physical Review C - Nuclear Physics, 62(6), 649011-6490110.
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  Abstract: Lattice quantum chromodynamics results provide an opportunity to model, and extrapolate to finite baryon density, the properties of the quark-gluon plasma (QGP). Upon fixing the scale of the thermal coupling constant and vacuum energy to the lattice data, the properties of resulting QGP equations of state (EoS) are developed. We show that the physical properties of the dense matter fireball formed in heavy ion collision experiments at CERN-SPS are well described by the QGP-EoS we presented. We also estimate the properties of the fireball formed in early stages of nuclear collision, and argue that QGP formation must be expected down to 4OA GeV in central Pb-Pb interactions.
• Letessier, J., & Rafelski, J. (2000). Observing quark-gluon plasma with strange hadrons. INTERNATIONAL JOURNAL OF MODERN PHYSICS E-NUCLEAR PHYSICS, 9(2), 107-147.
• Letessier, J., & Rafelski, J. (2000). Observing quark-gluon plasma with strange hadrons. International Journal of Modern Physics E, 9(2), 107-147.
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  Abstract: We review the methods and results obtained in an analysis of the experimental heavy ion collision research program at nuclear beam energy of 160-200 A GeV. We study strange, and more generally, hadronic particle production experimental data. We discuss present expectations concerning how these observables will perform at other collision energies. We also present the dynamical theory of strangeness production and apply it to show that it agrees with available experimental results. We describe strange hadron production from the baryon-poor quark-gluon phase formed at much higher reaction energies, where the abundance of strange baryons and antibaryons exceeds that of nonstrange baryons and antibaryons.
• Letessier, J., Tounsi, A., & Rafelski, J. (2000). Low-m⊥ π⁺-π^- asymmetry enhancement from hadronization of QGP. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 475(3-4), 213-219.
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  Abstract: We show that in sudden hadronization of QGP a non-equilibrium value of the pion phase space occupancy parameter γq> 1 is expected in order to accommodate the entropy excess in QGP and the process of gluon fragmentation. When γq is near to its maximum allowed value, pion overabundance is shown to arise at low m⊥, where the charged pion asymmetry is also amplified. These effects are considered and we show that their magnitude suffices to explain pertinent experimental data obtained in 160-200 A GeV Pb- and S- induced reactions. © 2000 Elsevier Science B.V.
• Quercigh, E., & Rafelski, J. (2000). A strange quark plasma. Physics World, 13(10), 37-42.
• Rafelski, J., & Letessier, J. (2000). Sudden hadronization in relativistic nuclear collisions. PHYSICAL REVIEW LETTERS, 85(22), 4695-4698.
• Rafelski, J., & Letessier, J. (2000). Sudden hadronization in relativistic nuclear collisions. Physical Review Letters, 85(22), 4695-4698.
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  Abstract: A constraint that relates the physical and statistical properties of the hadronic fireball at the point of sudden breakup was introduced. The constraint was shown to be consistent with analysis results obtained considering the experimental particle production data for Pb-Pb collisions at 158A GeV.
• Schroedter, M., Thews, R. L., & Rafelski, J. (2000). B-c-meson production in ultrarelativistic nuclear collisions. PHYSICAL REVIEW C, 62(2).
• Schroedter, M., Thews, R. L., & Rafelski, J. (2000). B_c-meson production in ultrarelativistic nuclear collisions. Physical Review C - Nuclear Physics, 62(2), 249051-249058.
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  Abstract: We study quantitatively the formation and evolution of b̄c, bc̄ bound states in a space-time domain of deconfined quarks and gluons (quark-gluon plasma, QGP). At the Relativistic Heavy Ion Collider (RHIC), one expects for the first time that typical central collisions will result in multiple pairs of heavy (in this case charmed) quarks. This provides a new mechanism for the formation of heavy quarkonia which depends on the properties of the deconfined region. We find typical enhancements of about 500-fold for the b̄c, bc̄ production yields over expectations from the elementary coherent hadronic Bc-meson production scenario. The final population of bound states may serve as a probe of the plasma phase parameters.
• Walton, D. B., & Rafelski, J. (2000). Equilibrium Distribution of Heavy Quarks in Fokker-Planck Dynamics. Physical Review Letters, 84(1), 31-34.
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  Abstract: We obtain an explicit generalization, within Fokker-Planck dynamics, of Einstein's relation between drag, diffusion, and the equilibrium distribution for a spatially homogeneous system, considering both the transverse and longitudinal diffusion for dimension n > I. We provide a complete characterization of the equilibrium distribution in terms of the drag and diffusion transport coefficients. We apply this analysis to charm quark dynamics in a thermal quark-gluon plasma for the case of collisional equilibration.
• Walton, D. B., & Rafelski, J. (2000). Equilibrium distribution of heavy quarks in Fokker-Planck dynamics. PHYSICAL REVIEW LETTERS, 84(1), 31-34.
• , J. L., & , J. R. (1999). Chemical non-equilibrium and deconfinement in 200 A GeV Sulphur induced reactions. Phys.Rev. C, 947-954.
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  We interpret hadronic particle abundances produced in S--Au/W/Pb 200 A GeVreactions in terms of the final state hadronic phase space model and determineby a data fit of the chemical hadron freeze-out parameters. Allowing for theflavor abundance non-equilibrium a highly significant fit to experimentalparticle abundance data emerges, which supports possibility of strangenessdistillation. We find under different strategies stable values for freeze-outtemperature T_f=143\pm3 MeV, baryochemical potential \mu_B= 173\pm6 MeV, ratioof strangeness (\gamma_s) and light quark (\gamma_q) phase space occupancies\gamma_s/\gamma_q=0.60\pm0.02, and \gamma_q=1.22\pm0.05 without accounting forcollective expansion (radial flow). When introducing flow effects which allow aconsistent description of the transverse mass particle spectra, yielding|v_c|=0.49\pm0.01c, we find \gamma_s/\gamma_q=0.69\pm0.03,\gamma_q=1.41\pm0.08. The strange quark fugacity is fitted at\lambda_s=1.00\pm0.02 suggesting chemical freeze-out directly from thedeconfined phase.[Journal_ref: Phys.Rev. C59 (1999) 947-954]
• Bass, S. A., Bleicher, M., Cassing, W., Dumitru, A., Drescher, H. J., Eskola, K. J., Gyulassy, M., Kharzeev, D., Kovchegov, Y. V., Lin, Z., Molnar, D., Ollitrault, J. Y., Pratt, S., Schlei, B. R., Sorge, H., Rafelski, J., Rapp, R., Rischke, D. H., Schaffner, J. B., , Snigirev, A. M., et al. (1999). Last call for RHIC predictions. NUCLEAR PHYSICS A, 661, 205C-260C.
• Bass, S. A., Bleicher, M., Cassing, W., Dumitru, A., Drescher, H. J., Eskola, K. J., Gyulassy, M., Kharzeev, D., Kovchegov, Y. V., Lin, Z., Molnar, D., Ollitrault, J. Y., Pratt, S., Schlei, B. R., Sorge, H., Rafelski, J., Rapp, R., Rischke, D. H., Schaffner, J. B., , Snigirev, A. M., et al. (1999). Last call for RHIC predictions. Nuclear Physics A, 661(1-4), 205c-260c.
• Elze, H. T., Hama, Y., Kodama, T., Makler, M., & Rafelski, J. (1999). Variational principle for relativistic fluid dynamics. JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS, 25(9), 1935-1957.
• Elze, H., Hama, Y., Kodama, T., Makler, M., & Rafelski, J. (1999). Variational principle for relativistic fluid dynamics. Journal of Physics G: Nuclear and Particle Physics, 25(9), 1935-1957.
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  Abstract: The variational principle for the special and general relativistic hydrodynamics is discussed in view of its application to obtain approximate solutions to these problems. We show that effective Lagrangians can be obtained for suitable ansatze for the dynamical variables such as the density profile of the system. As an example, the relativistic version of spherical droplet motion (Rayleigh-Plesset equation) is derived from a simple Lagrangian. For the general relativistic case the most general Lagrangian for spherically symmetric systems is given.
• Kodama, T., Elze, H., Hama, Y., Makler, M., & Rafelski, J. (1999). Variational principle for relativistic fluid dynamics. Acta Physica Hungarica New Series Heavy Ion Physics, 10(2-3), 275-285.
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  Abstract: Variational principles for special and general relativistic hydrodynamics are discussed with a view to their application to obtain approximate solutions to these problems. We show that effective Lagrangians can be obtained for a suitable ansatz for the dynamical variables such as the density profile of the system. As an example, the relativistic version of spherical droplet motion (Rayleigh-Plesset equation) is derived from a simple Lagrangian. For the general relativistic case the most general Lagrangian for spherically symmetric systems is given.
• Letessier, J., & Rafelski, J. (1999). Chemical nonequilibrium and deconfinement in 200A GeV sulphur induced reactions. PHYSICAL REVIEW C, 59(2), 947-954.
• Letessier, J., & Rafelski, J. (1999). Chemical nonequilibrium and deconfinement in 200A GeV sulphur induced reactions. Physical Review C - Nuclear Physics, 59(2), 947-954.
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  Abstract: We interpret hadronic particle abundances produced in S-Au/W/Pb 200A GeV reactions in terms of the final state hadronic phase space model and determine by a data fit of the chemical hadron freeze-out parameters. Allowing for the flavor abundance nonequilibrium a highly significant fit to experimental particle abundance data emerges, which supports the possibility of strangeness distillation. We find under different strategies stable values for freeze-out temperature Tf=143±3 MeV, baryochemical potential μB=173 ±6 MeV, ratio of strangeness (γs) and light quark (γq) phase space occupancies γs/γq=0.60±0.02, and γq=1.22±0.05 without accounting for collective expansion (radial flow). When introducing flow effects which allow a consistent description of the transverse mass particle spectra, yielding |ῡc|=0.49±0.01 c, we find γs/γq=0.69±0.03, γq=1.41±0.08. The strange quark fugacity is fitted at λs=1.00±0.02 suggesting chemical freeze-out directly from the deconfined phase.
• Letessier, J., & Rafelski, J. (1999). Chemical nonequilibrium in high-energy nuclear collisions. JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS, 25(2), 295-309.
• Letessier, J., & Rafelski, J. (1999). Chemical nonequilibrium in high-energy nuclear collisions. Journal of Physics G: Nuclear and Particle Physics, 25(2), 295-309.
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  Abstract: Strange particles produced in S-Au/W/Pb 200 A GeV and Pb-Pb 158 A GeV reactions are described invoking final hadronic phase space in thermal equilibrium, but allowing chemical nonequilibrium. Several sets of statistical freeze-out parameters are obtained for each system, invoking different models of dense matter. We show that only when allowing for strange and non-strange flavour abundance nonequilibrium, a statistically significant description of the experimental results is obtained. Physical properties of the fireball at chemical freeze-out condition are evaluated and considerable universality of hadron freeze-out between the two different collision systems is established. The relevance of the Coulomb effect in the highly charged Pb-Pb fireballs for the chemical analysis are discussed. The influence of explosive collective matter flow is also described.
• Letessier, J., & Rafelski, J. (1999). Quark-gluon plasma in PB-PB 158 a GEV collisions: Evidence from strange particle abundances and the coulomb effect. Acta Physica Polonica B, 30(1), 153-168.
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  Abstract: The hadronic particle production data from relativistic nuclear Pb-Pb 158 A GeV collisions are successfully described within the chemical non-equilibrium model, provided that the analysis treats Ω and Ω̄ abundances with care. We further show that there is a subtle influence of the Coulomb potential on strange quarks in quark matter which is also seen in our data analysis, and this Coulomb effect confirms the finding made by chemical analysis in the S-Au/W/Pb 200 A GeV collisions that the hadron particle source is deconfined with respect to strange quark propagation. Physical freeze-out conditions (pressure, specific energy, entropy, and strangeness) are evaluated and considerable universality of hadron freeze-out between the two different collision systems is established.
• Letessier, J., & Rafelski, J. (1999). Strange particle chemical freeze-out. Nuclear Physics A, 661(1-4), 497c-501c.
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  Abstract: In an analysis of hadron abundances and spectra we determine the properties of a disintegrating, hadron evaporating, deconfined quark-gluon plasma phase fireball for the case of nuclear collisions at 158-200A GeV. We argue that there is convincing evidence for the direct evaporation of hadrons from the quark-gluon plasma.
• Rafelski, J. (1999). Quo vadis strangeness?. Journal of Physics G: Nuclear and Particle Physics, 25(2), 451-468.
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  Abstract: The study of strange and also charmed hadronic particle production in nuclear relativistic collisions offers an opportunity to explore the physical properties of the deconfined quark-gluon phase. We survey the recent accomplishments and the future directions of this research programme.
• Rafelski, J., & Letessier, J. (1999). Diagnosis of QGP with strange hadrons. Acta Physica Polonica B, 30(12), 3559-3583. doi:https://www.actaphys.uj.edu.pl/R/30/12/3559/pdf
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  We review the current status of strangeness as signature of the formation and dissociation of the deconfined QGP at the SPS energy scale, and present the status of our considerations for RHIC energies. By analyzing, within the framework of a Fermi statistical model, the hadron abundance and spectra, the properties of a disintegrating, hadron evaporating, deconfined QGP fireball are determined and can be compared with theory for the energy range 160-200.A GeV on fixed target. We discuss in more detail our finding that the pion yields occur near to pion condensation condition. Dynamical models of chemical strangeness equilibration are developed and applied to obtain strangeness production in a QGP phase at conditions found at SPS and expected at RHIC. The sudden QGP break up model that works for the SPS data implies at RHIC dominance of both baryon, and antibaryon, abundances by the strange baryon and antibaryon yields.
• Rafelski, J., & Letessier, J. (1999). Expected production of strange baryons and antibaryons in baryon-poor QGP. PHYSICS LETTERS B, 469(1-4), 12-18.
• Rafelski, J., & Letessier, J. (1999). Expected production of strange baryons and antibaryons in baryon-poor QGP. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 469(1-4), 12-18.
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  Abstract: In a dynamical model of QGP at RHIC we obtain the temporal evolution of strange phase space occupancy at conditions expected to occur in 100 + 100 A GeV nuclear collisions. We show that the sudden QGP break up model developed to describe the SPS experimental results implies dominance of both baryon and antibaryon abundances by the strange baryon and antibaryon yields. © 1999 Published by Elsevier Science B.V. All rights reserved.
• Rafelski, J., & Müller, B. (1999). Quarks unleashed at low energy. Physics World, 12(3), 23-24.
• Thews, R., Schroedter, M., & Rafelski, J. (1999). B_c production at RHIC as a signal for deconfinement. Acta Physica Polonica B, 30(12), 3637-3646.
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  Abstract: The Bc meson is the bound state of bc̄ (or b̄c) whose recent detection is the first step toward completion of the spectroscopy of heavy quark mesonic states. The b-c states have properties that conveniently fill the gap between the J/ψ and the γ states. Thus it is probable that at RHIC the Bc mesons will serve as a probe of deconfined matter. We find that significant differences arise for Bc formation in deconfined and confined matter. Our initial calculations suggest that: (a) The rates of normal hadronic production mechanisms at RHIC energies are not sufficient to produce a detectable number of Bc mesons. (b) If a region of deconfined quarks and gluons is formed, the production (and survival) rate can be enhanced by several orders of magnitude. (c) The observation of Bc mesons at RHIC would signal a source of deconfined charmed quarks, and the rate of Bc production will be a measure of the initial density and temperature of that source.
• Cougo-Pinto, M., Farina, C., Tort, A., & Rafelski, J. (1998). Magnetic permeability in constrained fermionic vacuum. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 434(3-4), 388-395.
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  Abstract: We obtain using Schwinger's proper time approach the Casimir-Euler-Heisenberg effective action of fermion fluctuations for the case of an applied magnetic field. We implement here the compactification of one space dimension into a circle through anti-periodic boundary condition. Aside of higher order non-linear field effects we identify a novel contribution to the vacuum permeability. These contributions are exceedingly small for normal electromagnetism due to the smallness of the electron Compton wavelength compared to the size of the compactified dimension, if we take the latter as the typical size of laboratory cavities, but their presence is thought provoking, also considering the context of strong interactions. © 1998 Elsevier Science B.V. All rights reserved.
• Elze, H., Kodama, T., & Rafelski, J. (1998). Sound of sonoluminescence. Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics, 57(4), 4170-4185.
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  Abstract: We consider an air bubble in water under conditions of single-bubble sonoluminescence (SBSL) and evaluate the emitted sound field nonperturbatively for subsonic gas-liquid interface motion. Sound emission being the dominant damping mechanism, we also implement the nonperturbative sound damping in the Rayleigh-Plesset equation for the interface motion. We evaluate numerically the sound pulse emitted during bubble collapse and compare the nonperturbative and perturbative results, showing that the usual perturbative description leads to an overestimate of the maximal surface velocity and maximal sound pressure. The radius vs time relation for a full SBSL cycle remains deceptively unaffected.
• Rafelski, J. (1998). Melting the vacuum. Physics World, 11(2), 29-30.
• Rafelski, J. (1998). QCD-bag mass spectrum and phase transitions. Fourth Workshop on QCD, The American University of Paris (June 1998). doi:https://doi.org/10.48550/arXiv.hep-ph/9811290
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  We obtain the hadronic mass spectrum in the `bag of bags' statisticalbootstrap model (BBSBM), implementing the colorless state condition, aside ofbaryon and strangeness conservation, using group projection method. We studythe partition function, investigate the properties of dense hadronic matter,and determine the conditions under which the system undergoes a phasetransition to a deconfined quark-gluon plasma. We show that a phase transitioncannot occur in the N=1 (Abelian) limit of our model, and is first order forQCD-like case N=3.[Journal_ref: ]
• , J. R., , J. L., & , A. T. (1997). Thermal Flavor Production and Signatures of Deconfinement. Proceeding of ICHEP'.
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  Using renormalization group methods we evaluate the thermal strangeness andcharm chemical equilibrium relaxation times in the deconfined quark-gluonplasma. We present a reaction model and evaluate the total production rate ofstrangeness in fixed target Pb-Pb collisions at 10--300 A GeV. We discuss therelevance of our results to the diagnosis and understanding of the propertiesof the deconfined state.[Journal_ref: Proceeding of ICHEP'96, World Scientific, Singapore (1997)]
• Kodama, T., Elze, H., Rafelski, J., & Scott, I. (1997). Variational Approach to Hydrodynamics: Application to the Sonoluminescence Gas Bubble. Acta Physica Hungarica New Series Heavy Ion Physics, 5(4), 343-356.
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  Abstract: We develop a variational approximation allowing to study under realistic physical conditions the interior dynamics of cavitating gas bubbles in liquids. We discuss in some detail the intricacy of the gas bubble dynamics related to the small size of the system. We also show how to formulate the problem in the framework of the energy equation for non-adiabatic processes.
• Letessier, J., Rafelski, J., & Tounsi, A. (1997). QGP formation and strange antibaryons. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 390(1-4), 363-369.
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  Abstract: We explore, as function of the collision energy and stopping in relativistic nuclear collisions, the production yields of strange antibaryons, assuming formation of a deconfined thermal quark-gluon plasma (QGP) fireball which undergoes a sudden hadronisation. Aside of assumptions related to this reaction picture and QCD properties at this energy scale, our work does not contain (fitted) parameters.
• Letessier, J., Rafelski, J., & Tounsi, A. (1997). Strangeness in Pb-Pb collisions at 158 A GeV. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 410(2-4), 315-322.
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  Abstract: We study relative strange particle abundances measured in Pb-Pb 158 A GeV interactions. The thermal and chemical source parameters of these particles are determined under reaction scenario hypothesis invoking confined and deconfined hadronic matter. © 1997 Elsevier Science B.V.
• Rafelski, J., Letessier, J., & Tounsi, A. (1997). Hadronic signatures of deconfinement in relativistic nuclear collisions. Acta Physica Polonica B, 28(12), 2841-2872.
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  Abstract: We describe the remarkable accomplishments of the current heavy ion Pb-Pb collision experiments involving strange particle production, carried out at 158A GeV at CERN-SPS. Together with earlier 200A GeV S-induced reactions, these results imply that, at central rapidity, a novel mechanism of strangeness production arises, accompanied by excess entropy formation. We argue that: • these results are consistent with the formation of a space-time localized, highly excited, dense state of matter; • the freeze-out properties of strange hadrons are suggestive of the formation of a color-deconfined, thermally and nearly chemically equilibrated phase, which provides at present the only comprehensive framework to describe all experimental data; • the matter fireball is undergoing a transverse expansion with nearly the velocity of sound of relativistic matter; longitudinal expansion is not in the scaling regime. We present a first analysis of the recent Pb-Pb results and discuss several alternative reaction scenarios. We evaluate quantitatively strangeness production in the deconfined quark-gluon phase and obtain yields in agreement with the experimental observations made in 200A GeV S-W and 158A GeV Pb-Pb interactions. We also present a qualitative discussion of J/ψ results consistent with our understanding of strange particle results.
• , J. R., , J. L., & , A. T. (1996). Strange Particles from Dense Hadronic Matter. Acta Phys.Polon. B, 1037-1140.
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  After a brief survey of the remarkable accomplishments of the current heavyion collision experiments up to 200A GeV, we address in depth the role ofstrange particle production in the search for new phases of matter in thesecollisions. In particular, we show that the observed enhancement pattern ofotherwise rarely produced multistrange antibaryons can be consistentlyexplained assuming color deconfinement in a localized, rapidly disintegratinghadronic source. We develop the theoretical description of this source, and inparticular study QCD based processes of strangeness production in thedeconfined, thermal quark-gluon plasma phase, allowing for approach to chemicalequilibrium and dynamical evolution. We also address thermal charm production.Using a rapid hadronization model we obtain final state particle yields,providing detailed theoretical predictions about strange particle spectra andyields as function of heavy ion energy. Our presentation is comprehensive andself-contained: we introduce in considerable detail the procedures used in datainterpretation, discuss the particular importance of selected experimentalresults and show how they impact the theoretical developments.[Journal_ref: Acta Phys.Polon. B27 (1996) 1037-1140]
• Letessier, J., Rafelski, J., & Tounsi, A. (1996). Impact of QCD and QGP properties on strangeness production. PHYSICS LETTERS B, 389(3), 586-594.
• Letessier, J., Rafelski, J., & Tounsi, A. (1996). Impact of QCD and QGP properties on strangeness production. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 389(3), 586-594.
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  Abstract: Employing running QCD renormalization group parameters αs(μ) and ms(μ) we obtain strangeness production yields in the deconfined quark-gluon plasma (QGP) phase. We model a dynamically evolving QGP fireball as could be formed in relativistic nuclear collisions and obtain the total strangeness per baryon yield as function of energy and impact parameter. We also study strangeness phase space occupancy varying the hadronization and freeze-out conditions of the expanding QGP fireball.
• Rafelski, J., Letessier, J., & Tounsi, A. (1996). Strange particles from dense hadronic matter. ACTA PHYSICA POLONICA B, 27(5), 1037-1140.
• Rafelski, J., Letessier, J., & Tounsi, A. (1996). Strange particles from dense hadronic matter. Acta Physica Polonica B, 27(5), 1037-1140.
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  Abstract: After a brief survey of the remarkable accomplishments of the current heavy ion collision experiments up to 200A GeV, we address in depth the role of strange particle production in the search for new phases of matter in these collisions. In particular, we show that the observed enhancement pattern of otherwise rarely produced multistrange antibaryons can be consistently explained assuming color deconfinement in a localized, rapidly disintegrating hadronic source. We develop the theoretical description of this source, and in particular study QCD based processes of strangeness production in the deconfined, thermal quark-gluon plasma phase, allowing for approach to chemical equilibrium and dynamical evolution. We also address thermal charm production. Using a rapid hadronization model we obtain final state particle yields, providing detailed theoretical predictions about strange particle spectra and yields as functions of heavy ion energy. Our presentation is comprehensive and self-contained: we introduce the procedures used in data interpretation in considerable detail, discuss the particular importance of selected experimental results, and show how they impact the theoretical developments.
• Rafelski, J., Letessier, J., & Tounsi, A. (1996). Thermal strangeness and charm in QGP. Acta Physica Hungarica New Series Heavy Ion Physics, 4(1-4), 181-192.
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  Abstract: Using QCD methods we re-evaluate strangeness and charm production in a thermal QGP fireball. QCD renormalization group is employed to evaluate running of the parameters αs(μ) and ms(μ). We resum even-αs Feynman diagrams involving two particles in initial and final states. We obtain thermal relaxation times in a simple dynamical description of the fireball and we use these results to study two generic strangeness observables as function of collision energy: specific (per baryon) strangeness yield (s̄)/B, and phase space occupancy γs. From these two quantities, knowing the hadronization process in rough detail, we obtain the final state strange particle abundances. © 1996 Akadémiai Kiadó, Budapest.
• LETESSIER, J., TOUNSI, A., HEINZ, U., SOLLFRANK, J., & RAFELSKI, J. (1995). STRANGENESS CONSERVATION IN HOT NUCLEAR FIREBALLS. PHYSICAL REVIEW D, 51(7), 3408-3435.
• Letessier, J., Rafelski, J., & Tounsi, A. (1995). Strange antibaryons from QGP. Nuclear Physics, Section A, 590(1-2), 613-616.
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  Abstract: We study as function of the collision energy and stopping the thermal conditions reached in a quark-gluon plasma fireball formed in a relativistic heavy ion collision. We explore strange particle yields for the current round of PbPb and AuAu experiments. © 1995.
• Letessier, J., Tounsi, A., Heinz, U., Sollfrank, J., & Rafelski, J. (1995). Strangeness conservation in hot nuclear fireballs. Physical Review D, 51(7), 3408-3435.
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  Abstract: Within a thermal model generalized to allow for nonequilibrium strange particle abundances we study how the constraint that the balance of strangeness in a fireball is (nearly) zero impacts the allowable thermal fireball parameters. Using the latest data of the CERN-WA85 experiment for the case of 200A GeV S-A (A∼200) collisions we extract the values of the thermal parameters considering in detail the impact of hadronic resonance decays on the abundances and spectral form of strange baryons and antibaryons. Given these results and invoking further the observed charged particle multiplicities we are able to consider the (specific) entropy content of the fireball in order to understand the nature of the disagreement of the hadronic gas picture of the fireball with the experimental data. © 1995 The American Physical Society.
• Shin, G. R., & Rafelski, J. (1995). Relativistic Transport Equations for Electromagnetic, Scalar, and Pseudoscalar Potentials. Annals of Physics, 243(1), 65-75.
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  Abstract: We propose a particular form of relativistic transport equations arising from the classical limit of single-time Wigner function for Dirac particles evolving in the presence of scalar, pseudoscalar, and electromagnetic fields. These relativistic Vlasov-type equations for the particle and the antiparticle sector of the Fock space can be also obtained assuming the validity of the Liouville′s equation given a suitable classical Hamiltonian and the associated force. © 1995 Academic Press. All rights reserved.
• LETESSIER, J., RAFELSKI, J., & TOUNSI, A. (1994). GLUON PRODUCTION, COOLING, AND ENTROPY IN NUCLEAR COLLISIONS. PHYSICAL REVIEW C, 50(1), 406-409.
• LETESSIER, J., RAFELSKI, J., & TOUNSI, A. (1994). STRANGE PARTICLE ABUNDANCE IN QGP FORMED IN 200 GEV-A NUCLEAR COLLISIONS. PHYSICS LETTERS B, 323(3-4), 393-400.
• LETESSIER, J., RAFELSKI, J., & TOUNSI, A. (1994). STRANGE PARTICLE FREEZE-OUT. PHYSICS LETTERS B, 321(4), 394-399.
• LETESSIER, J., RAFELSKI, J., & TOUNSI, A. (1994). STRANGENESS AND PARTICLE FREEZE-OUT IN NUCLEAR COLLISIONS AT 14.6 GEV A. PHYSICS LETTERS B, 328(3-4), 499-505.
• Letessier, J., Rafelski, J., & Tounsi, A. (1994). Formation and evolution of the quark-gluon plasma. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 333(3-4), 484-493.
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  Abstract: Imposing an equilibrium between the thermal pressure of deconfined quarks and gluons and the dynamical compression pressure exercised by in-flowing nuclear matter, we study the initial thermal conditions reached in a quark-gluon plasma fireball formed in a relativistic heavy ion collision. We show that entropy is produced primarily in the pre-equilibrium stage of the reaction. We test our approach, comparing our results with the S→W/Pb collision results at 200 GeV A and find a surprising degree of agreement assuming about 50% stopping. We apply our method to a determination of the conditions in collisions of Au→Au at 11 GeV A and Pb→Pb at 157 GeV A, assuming full stopping of momentum, energy and baryon number. Our detailed results directly determine the spectral shape and abundance of (strange) hadrons and electromagnetic probes (photons, dileptons) produced in the collision, and we explore specific experimental consequences.
• Letessier, J., Rafelski, J., & Tounsi, A. (1994). Gluon production, cooling, and entropy in nuclear collisions. Physical Review C, 50(1), 406-409.
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  Abstract: We study the cooling (heating) of a glue-parton gas due to production (destruction) of particles and determine the associated evolution of entropy. We incorporate sharing of the system energy among a changing number of particles. We find that the entropy of an evolving glue-parton gas hardly changes, once the initial thermalized state has been formed, despite a significant change in particle number and temperature. © 1994 The American Physical Society.
• Letessier, J., Rafelski, J., & Tounsi, A. (1994). Strange particle abundance in QGP formed in 200 GeV a nuclear collisions. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 323(3-4), 393-400.
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  Abstract: We investigate the relative abundance of strange particles produced in nuclear collisions at the SPS energies (∼ 9 GeV A in CM frame) assuming that the central reaction fireball consists of quark-gluon plasma. We show that the total strangeness yield observed in Sulphur induced reactions is compatible with this picture.
• Letessier, J., Rafelski, J., & Tounsi, A. (1994). Strange particle freeze-out. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 321(4), 394-399.
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  Abstract: We reconsider thermal conditions of the central fireball presumed to be the source of abundantly produced strange (anti-) baryons in S → W collisions at 200 GeV A. We show that it is possible to completely fix the freeze-out temperature of strange particles in terms of the central rapidity kaon to Lambda particle abundance ratio at fixed, high transverse mass using a non-equilibrium hadronization model and the measured quark fugacities.
• Letessier, J., Rafelski, J., & Tounsi, A. (1994). Strangeness and particle freeze-out in nuclear collisions at 14.6 GeV A. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 328(3-4), 499-505.
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  Abstract: We study the chemical conditions at freeze-out associated with the production of strange-particles in Si-Au collisions at 14.6 GeV A. We obtain freeze-out chemical potentials and temperature, and determine the entropy as well as the final particle abundance. We also consider in detail the alternative evolution scenarios involving the hadronic gas and the deconfined phase.
• Rafelski, J., & Danos, M. (1994). Strangeness flow difference in nuclear collisions at 15A and 200A GeV. Physical Review C, 50(3), 1684-1687.
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  Abstract: We show existence of an important difference between strange-particle production in Si-Au collisions at 15A GeV (AGS) and in S-A collisions at 200A GeV (CERN), with A=32 and A=0 (200). © 1994 The American Physical Society.
• SOLLFRANK, J., GAZDZICKI, M., HEINZ, U., & RAFELSKI, J. (1994). CHEMICAL FREEZE-OUT CONDITIONS IN CENTRAL S-S COLLISIONS AT 200-A GEV. ZEITSCHRIFT FUR PHYSIK C-PARTICLES AND FIELDS, 61(4), 659-665.
• Sollfrank, J., Gaździcki, M., Heinz, U., & Rafelski, J. (1994). Chemical freeze-out conditions in central S-S collisions at 200 A GeV. Zeitschrift für Physik C Particles and Fields, 61(4), 659-665.
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  Abstract: We determine the chemical freeze-out parameters of hadronic matter formed in central S-S collisions at 200 A GeV, analyzing data from the NA35 collaboration at CERN. In particular we study the quark (baryon number) and strange quark fugacities, as well as the strange quark phase-space occupancy and the freeze-out temperature. The strange quark chemical potential is found to be consistent with zero, and the strange quark abundance is found to be saturated as would be expected for the deconfined phase. We study the stability of our results against variations in the analysis procedure and with respect to a restriction of the data to the central rapidity region. The same analysis applied to nucleonnucleon data yields significantly different freeze-out parameters, in particular regarding the degree of strangeness saturation. © 1994 Springer-Verlag.
• Białynicki-Birula, I., Davis, E. D., & Rafelski, J. (1993). Evolution modes of the vacuum Wigner function in strong-field QED. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 311(1-4), 329-338.
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  Abstract: The physical content of a non-covariant quantum-field theoretic transport formalism for strong-field QED is addressed within an integral formulation of the evolution equations which highlights the relation to acoustic and Zitterbewegung modes of the field-free limit. Through the computation within this framework of the electric susceptibility of the vacuum at the one-loop level, it is established that the off-shell behaviour of the electron-positron field is correctly incorporated. The Zitterbewegung mode is seen to be solely responsible at the one-loop level for vacuum polarization. Implications for the full renormalisation of the theory are taken up.
• LETESSIER, J., TOUNSI, A., HEINZ, U., SOLLFRANK, J., & RAFELSKI, J. (1993). EVIDENCE FOR A PHASE WITH HIGH SPECIFIC ENTROPY IN NUCLEAR COLLISIONS. PHYSICAL REVIEW LETTERS, 70(23), 3530-3533.
• Letessier, J., Tounsi, A., Heinz, U., Sollfrank, J., & Rafelski, J. (1993). Evidence for a phase with high specifie entropy in nuclear collisions. Physical Review Letters, 70(23), 3530-3533.
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  Abstract: We determine the entropy-per-baryon content of the central reaction region in terms of the charged particle multiplicity. We study the consistency of our findings with recent data on strange antibaryon production at 200A GeV in S-A collisions (A ∼200) assuming formation of a central fireball. Hadron gas models which do not invoke strong medium modifications of hadron masses do not provide enough entropy and are inconsistent with the combined experimental results. In contrast the quark-gluon plasma hypothesis explains them naturally.
• Shin, G. R., & Rafelski, J. (1993). Relativistic classical limit of quantum theory. Physical Review A, 48(3), 1869-1874.
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  Abstract: We study the classical limit of the equal-time relativistic quantum transport theory. We discuss in qualitative terms the need to fold first the Wigner function with a coarse-graining function. Only then does the singularity at Latin small letter h with stroke→0 seem to be manageable. In the limit Latin small letter h with stroke→0, we obtain the relativistic Vlasov equations for the particle and the antiparticle sector of the Fock space. Similarly, we address the evolution equations of the spin and the magnetic-moment density. © 1993 The American Physical Society.
• Elze, H., & Rafelski, J. (1992). Collective Higgs production in high-energy heavy-ion collisions. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 276(4), 501-510.
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  Abstract: In heavy-ion collisions involving the formation of high-energy-density forms of nuclear matter (QGP) the rapid change of the scalar matter density 〈Ψ̄Ψ〈 leads to collective and often subthreshold Higgs production. We calculate the rapidity spectra of such Higgs particles qualitatively in the Bjorken collision scenario and, for comparison, in the model of a spherically expanding fireball and consider various options for experiments.
• Elze, H., & Rafelski, J. (1992). Collective hadronic Higgs production in heavy-ion collisions. Nuclear Physics, Section A, 544(1-2), 585-590.
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  Abstract: We study collective and subthreshold Higgs production due to the formation of high energy density matter (QGP) associated with a rapid change of the scalar density 〈ππ〉. The rapidity spectra of Higgs particles are discussed in the Bjorken collision scenario and for a spherically expanding fireball. We briefly consider options for experiments. © 1992.
• LETESSIER, J., TOUNSI, A., & RAFELSKI, J. (1992). HOT HADRONIC MATTER AND STRANGE ANTI-BARYONS. PHYSICS LETTERS B, 292(3-4), 417-423.
• Letessier, J., Tounsi, A., & Rafelski, J. (1992). Hot hadronic matter and strange anti-baryons. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 292(3-4), 417-423.
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  Abstract: We demonstrate that both quark-gluon plasma (QGP) and hadronic gas (HG) models of the central fireball created in S → W collisions at 200A GeV are possible sources of the recently observed strange (anti-)baryons. From the theoretical point of view, the HG interpretation we attempt remains more obscure because of the high fireball temperature required. The thermal properties of the fireball as determined by the particle ratios are natural for the QGP state. We show that the total particle multiplicity emerging from the central rapidity region allows to distinguish between the two scenarios.
• Rafelski, J. (1992). STRANGE AND HOT MATTER. NUCLEAR PHYSICS A, 544(1-2), C279-C292.
• Rafelski, J. (1992). Strange and hot matter. Nuclear Physics, Section A, 544(1-2), 279-292.
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  Abstract: I consider the strangeness degree of freedom in hot nuclear matter and its significance for the observation and identification of a quark-gluon plasma. Particular attention is given to the interpretation of new and intriguing results on strange antibaryon production. © 1992.
• Rafelski, J., Rafelski, H., & Danos, M. (1992). Strange fireballs. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 294(1), 131-138.
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  Abstract: The features of strange particle spectra originating in a fireball at central rapidity having local kinetic equilibrium are studied in detail. A comparison with recently presented experimental data suggests that the origin of the abundantly produced strange particles is a rapidly disintegrating central fireball. Critical characteristic features of the spectra, such as the shapes of rapidity distributions and the relation between the intrinsic temperature of the fireball and the observed experimental slopes of transverse mass spectra are discussed including the dependence on the experimental cuts.
• Shin, G. R., Bialynicki-Birula, I., & Rafelski, J. (1992). Wigner function of relativistic spin-1/2 particles. Physical Review A, 46(1), 645-647.
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  Abstract: Using the recently developed relativistic Wigner formulation for the density matrix of spin-1/2 particles, we study the =1/2+ Coulomb-like and cavity relativistic states. One of our objectives is to understand the sharing of the total angular momentum of a quantum state between the spin and rotational degrees of freedom, arising due to the spin-orbit coupling. Another is to demonstrate that the 4×4-matrix Wigner function is the appropriate generalization from the 2×2 form of the nonrelativistic theory. © 1992 The American Physical Society.
• BI, P. Z., & RAFELSKI, J. (1991). DECAY OF PHI IN HOT MATTER. PHYSICS LETTERS B, 262(4), 485-491.
• BIALYNICKIBIRULA, I., GORNICKI, P., & RAFELSKI, J. (1991). PHASE-SPACE STRUCTURE OF THE DIRAC VACUUM. PHYSICAL REVIEW D, 44(6), 1825-1835.
• Bi, P., & Rafelski, J. (1991). Decay of φ in hot matter. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 262(4), 485-491.
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  Abstract: We investigate how the presence of hadronic matter affects the width and the decay pattern of φ as a function of temperature and density and what this means qualitatively for the experiments studying φ production in relativistic nuclear collisions. We determine quantitatively in two models how the natural hadronic width of φ increases in a hot hadronic gas.
• Bialynicki-Birula, I., Garnicki, P., & Rafelski, J. (1991). Phase-space structure of the Dirac vacuum. Physical Review D, 44(6), 1825-1835.
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  Abstract: We study the phase-space correlation function for the Dirac vacuum in the presence of simple field configurations. Our formalism rests on the Wigner transform of the Dirac-Heisenberg correlation function of the Dirac field coupled to the electromagnetic field. A self-consistent set of equations obeyed by the 16 components of the phase-space correlation function and by the electric and magnetic field is derived. Our approach is manifestly gauge invariant. A closed system of integro-differential equations is obtained neglecting the quantum fluctuations of the electromagnetic field as should be appropriate for strong fields. These equations are an extension of the Vlasov equations used in the description of plasma. Our first applications address the production of particles in strong external fields. We set a framework for the inclusion of the back reaction of produced particles and for the description of the local changes of the vacuum state. © 1991 The American Physical Society.
• EGGERS, H. C., & RAFELSKI, J. (1991). STRANGENESS AND QUARK GLUON PLASMA - ASPECTS OF THEORY AND EXPERIMENT. INTERNATIONAL JOURNAL OF MODERN PHYSICS A, 6(7), 1067-1113.
• Gajda, M., & Rafelski, J. (1991). Jovian limits on conventional cold fusion. Journal of Physics G: Nuclear and Particle Physics, 17(5), 653-661.
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  Abstract: The authors evaluate the fusion rates occurring naturally and according to conventional wisdom in the planet Jupiter. In particular they consider if any significant part of Jupiter's excess heat could be due to fusion, and if significant limits arise for terrestrial cold fusion experiments.
• McGuire, P. C., Littlewort, G. C., & Rafelski, J. (1991). Brainwashing random asymmetric "neural" networks. Physics Letters A, 160(3), 255-260.
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  Abstract: An algorithm for synaptic modification (plasticity) is described by which a recurrently connected network of neuron-like units can organize itself to produce a sequence of activation states that does not repeat itself for a very long time. During the self-organization stage, the connections between the units undergo non-Hebbian modifications, which tend to decorrelate the activity of the units, thereby lengthening the period of the cyclic modes inherent in the network. It is shown that the peridiodicity of the activity rises exponentially with the amount of exposure to this plasticity algorithm. Threshold is also a critical parameter in determining cycle lengths, as is the rate of decay of the fields that accumulate at silent units. © 1991.
• RAFELSKI, H. E., HARLEY, D., SHIN, G. R., & RAFELSKI, J. (1991). COLD FUSION - MUON-CATALYZED FUSION. JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS, 24(7), 1469-1516.
• Rafelski, H. E., Harley, D., Shin, G. R., & Rafelski, J. (1991). Cold fusion: Muon-catalysed fusion. Journal of Physics B: Atomic, Molecular and Optical Physics, 24(7), 1469-1516.
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  Abstract: The authors put into perspective and further develop their recent work in muon catalysed fusion, with the objective of identifying the key physical processes in the t(d,n) alpha fusion cycle relevant to energy related applications. They begin by discussing the fusion cycle and point out the importance of direct nuclear reactions in the catalysed fusion processes. This is followed by an in-depth discussion of the muon loss reaction by attachment to the fusion alpha -particle. Finally, the authors examine some special topics that have attracted the attention of workers in the muon-catalysed fusion (MuCF) community, such as energy efficient production of muons and proposals for MuCF reactors, the potential of Z>1 fusion, and other recently discussed forms of cold fusion. © 1991 IOP Publishing Ltd.
• Rafelski, J. (1991). STRANGE ANTI-BARYONS FROM QUARK-GLUON PLASMA. PHYSICS LETTERS B, 262(2-3), 333-340.
• Rafelski, J. (1991). Strange anti-baryons from quark-gluon plasma. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 262(2-3), 333-340.
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  Abstract: Experimental results on strange anti-baryon production in nuclear S→W collisions at 200 A GeV are described in terms of a simple model of an explosively disintegrating quark-lepton plasma (QGP). The importance of the strange anti-baryon signal for the identification of the QGP state and for the diagnosis of its properties is demonstrated.
• Rafelski, J., & Rafelski, H. E. (1991). Muon-Catalyzed Fusion. Advances in Atomic, Molecular and Optical Physics, 29(C), 177-215.
• Sawicki, M., Gajda, M., Harley, D., & Rafelski, J. (1991). Reactions of charged massive particles in a deuterium environment. Physical Review A, 44(7), 4345-4352.
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  Abstract: We consider paths to the observation of the ultraheavy, negatively charged particle, a possible remnant from the early Universe. In particular, we study the reactions in a deuterium environment. © 1991 The American Physical Society.
• Shin, G. R., & Rafelski, J. (1991). Muons after d-t fusion. Physical Review A, 43(1), 601-602.
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  Abstract: We consider the forces acting on the muon following the d-t fusion and show that it is improper to neglect the Coulomb interaction. We further show that the muon separation from the particle is large at the time both interact with matter. This invalidates the assumption of pointlike source for transport studies of the muon evolution. We conclude, therefore, that the comment made by Jändel is physically incorrect. © 1991 The American Physical Society.
• Harley, D., Muller, B., & Rafelski, J. (1990). Muon catalysed fusion of nuclei with Z>1. Journal of Physics G: Nuclear and Particle Physics, 16(2), 281-294.
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  Abstract: The authors investigate the processes involved in muon catalysis of hydrogen isotopes with light nuclei Z>1, with the objective of identifying systems in which at least one fusion per muon is possible. They systematically explore all nuclear systems and identify those having the potential to lead to fast fusion rates despite the high Coulomb barrier. They consider in some detail the tunnelling through this barrier as well as the internal conversion of the muon. Furthermore they establish, in qualitative terms, the necessary conditions for muomolecular rates in collisions of muonic atoms of hydrogen isotopes with small concentrations of light elements.
• Harley, D., Müller, B., & Rafelski, J. (1990). Time independent description of the t(d, n)α fusion reaction in the presence of a muon. Zeitschrift für Physik A Atomic Nuclei, 336(3), 303-312.
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  Abstract: We describe the (α n μ)-(d t μ) continuum above and below the d+(t μ)1s threshold using the R-matrix formalism. The continuum is explicitly constructed in an adiabatic approximation, and the asymptotic phase shifts and amplitudes in all channels are obtained. The energy eigenstates are used to compute the fusion reaction cross section for in-flight d+(t μ) fusion, and fusion reaction rates involving transitions from the d+(t μ)1s continuum to be below threshold continuum states. © 1990 Springer-Verlag.
• Harley, D., Soff, G., & Rafelski, J. (1990). Localized Higgs-fermion states. Journal of Physics G: Nuclear and Particle Physics, 16(10), L207-L212.
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  Abstract: The authors obtain spherically symmetric classical solutions to the strongly coupled Higgs-fermion fields in the electroweak SU(2) L*U(1)Y standard model. They find that there exists an upper limit on the physical mass of fermions due to the non-perturbative distortion of the Higgs vacuum in the vicinity of localized fermion solutions. For a reasonable range of Higgs masses, the upper limit on the fermion mass is of the order of 2 TeV.
• Jones, S. E., Palmer, E. P., Czirr, J. B., Decker, D. L., Jensen, G. L., Thorne, J. M., Taylor, S. F., & Rafelski, J. (1990). Anomalous nuclear reactions in condensed matter. Recent results and open questions. Journal of Fusion Energy, 9(2), 199-208.
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  Abstract: We have observed clear signatures for neutron emission during deuteron infusion into metals, implying the occurence of nuclear fusion in condensed matter near room temperature. The low-level nuclear phenomenon has been demonstrated in collaborative experiments at Brigham Young University, at the Gran Sasso laboratory in Italy, and at the Los Alamos National Laboratory. We have shown that neutron emission can be induced in metals using both electrochemical and variational temperature/pressure means to generate non-equilibrium conditions. Observed average neutron emission rates are approximately 0.04-0.4 n°/s. Current efforts focus on trying to understand and control the phenomenon. In particular, we wish to understand the correlation of neutron yields with parameters such as hydrogen/metal ion ratio, pressure (induced, for example, by electrical field or gas pressure or mechanical pressure), temperature variation, hydride phase changes, and surface conditions, e.g., a palladium coating on titanium. We want to know if fusion arises due to the close proximity of the deuterons in the lattice (piezonuclear fusion), or possibly from 'microscopic hot fusion' accompanying strong electric fields at propagating cracks in the hydride. The latter interpretation would imply neutron emission in bursts. Our experiments show clear evidence for emission of approximately 102 neutrons in bursts lasting < 128 μs, although random neutron-singles emissions were also observed. Experiments now underway to compare the d-d, and p-d, and d-t reaction rates will be important to a consistent description of the new phenomenon. Careful scrutiny of this effect could increase our understanding of heat, helium-3, and tritium production in the earth, other planets, and even the stars.
• Rafelski, J., Sawicki, M., Gajda, M., & Harley, D. (1990). How cold fusion can be catalyzed. Fusion Technology, 18(1), 136-142.
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  Abstract: A yet undiscovered ultra-heavy, negatively charged particle X-, a remnant from the early Universe, could be the origin of diverse cold fusion phenomena. The possibility that the random fusion neutrons reported by Jones et al. in association with electrolysis of heavy water may be caused by inflight X--induced reactions is considered in detail. The catalysis of other cold fusion phenomena such as heat production without penetrating radiation, or tritium production without production of neutrons, is also discussed.
• Sawicki, M., & Rafelski, J. (1990). Attenuation of the flux of neutrachamps in the Earth's atmosphere-a parametric study. Journal of Physics G: Nuclear and Particle Physics, 16(9), L197-L205.
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  Abstract: The authors estimate the attenuation of the flux of neutrachamps as they propagate through the Earth's atmosphere and discuss the possibility that they will reach the surface of the Earth.
• Shin, G. R., & Rafelski, J. (1990). Muons after d-t fusion. Journal of Physics G: Nuclear and Particle Physics, 16(9), L187-L195.
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  Abstract: The authors obtain and evolve in time the Wigner phase space distribution of the muon emerging from the catalysed (dt) fusion. The energy spectrum is calculated as function of time until the final amplitude at time= infinity is reached. In particular, the muon phase space distribution is allowed to evolve under the influence of the fusion alpha -particle. They find that the sticking amplitude is built up over rather large distances and that post fusion alpha - mu -hydrogen interactions are of importance.
• Shin, G. R., & Rafelski, J. (1990). Pion production for MuCF. Nuclear Inst. and Methods in Physics Research, A, 287(3), 565-569.
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  Abstract: We suggest a novel scheme for energy efficient, copious negative pion production: a stored proton beam collides with a thin metallic target producing primary π- and other shower particles. These high energetic secondaries produce further π- in external secondary targets. Estimations on energy cost per primary negative pion production for this scheme are given for proton beams and various targets. The secondary particle distributions according to momentum and angle are obtained with Monte Carlo simulation. The secondary neutron, proton and π+ efficiencies to produce negative pions are given. We find that a π- may be produced at a cost of 2.7 GeV in beam kinetic energy at Pp ≈ 4.8 GeV/c using Be targets. © 1990.
• JONES, S. E., PALMER, E. P., CZIRR, J. B., DECKER, D. L., JENSEN, G. L., THORNE, J. M., TAYLOR, S. F., & RAFELSKI, J. (1989). OBSERVATION OF COLD NUCLEAR-FUSION IN CONDENSED MATTER. NATURE, 338(6218), 737-740.
• Jones, S. E., Palmer, E. P., Czirr, J. B., Decker, D. L., Jensen, G. L., Thorne, J. M., Taylor, S. F., & Rafelski, J. (1989). Observation of cold nuclear fusion in condensed matter. Nature, 338(6218), 737-740.
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  Abstract: When a current is passed through palladium or titanium electrodes immersed in an electrolyte of deuterated water and various metal salts, a small but significant flux of neutrons is detected. Fusion of deuterons within the metal lattice may be the explanation. © 1989 Nature Publishing Group.
• Mrawczyński, S., & Rafelski, J. (1989). Parton bremsstrahlung as a mechanism of energy deposition in high-energy hadron-nucleus and nucleus-nucleus collisions. Physical Review C, 40(2), 1077-1080.
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  Abstract: On the basis of perturbative quantum chromodynamics, we consider the bremsstrahlung energy losses of partons traversing parton matter using the well-known quantum electrodynamical formulas. We find the transport equation describing the energy distribution of partons as a function of thickness of a target. The equation is solved numerically and we briefly discuss the relevance of our results for hadron-nucleus and nucleus-nucleus collisions at high energies. © 1989 The American Physical Society.
• M̈ller, B., Rafelski, H. E., & Rafelski, J. (1989). Muon spectrum and convoy effects after muon-catalyzed fusion. Physical Review A, 40(5), 2839-2842.
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  Abstract: We study final-state interactions of the muon after muon-catalyzed D-T fusion reaction with the ± particle and with target matter. The yield of convoy muons, traveling with the ± particle but remaining unbound is calculated. Energy loss in the dense target may lead to capture of a fraction of these muons into outer shells of the ± particle. We show that the final capture probability can be strongly density dependent. © 1989 The American Physical Society.
• RAFELSKI, H. E., MULLER, B., RAFELSKI, J., TRAUTMANN, D., & VIOLLIER, R. D. (1989). MUON REACTIVATION IN MUON-CATALYZED D-T FUSION. PROGRESS IN PARTICLE AND NUCLEAR PHYSICS, 22, 279-338.
• Rafelski, H. E., Müller, B., Rafelski, J., Trautmann, D., & Viollier, R. D. (1989). Muon reactivation in muon-catalyzed D-T fusion. Progress in Particle and Nuclear Physics, 22(C), 279-338.
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  Abstract: We comprehensively reanalyze and search for the density dependence of the effective muon alpha sticking fraction ωsff observed experimentally in muon catalyzed deuterium-tritium fusion. In our work particular emphasis has been put on the density dependent dense hydrogen stopping power. The main technical details and improvements in this work are: The (αμ)+ 2s and 2p states are treated independently and are assigned individual reaction rates. The essential muonic excitation rates have been recalculated taking into account finite nuclear mass effects. The stopping power for a charged projectile in liquid heavy hydrogen is modified to account for dynamic screening effects and a density dependent effective ionization potential. It is shown that the medium dependent stopping power for the (αμ)+ ion is the crucial factor controlling the density dependence of the effective sticking fraction. It is also pointed out that the muonic helium Kα X-ray yield and the sticking fraction at high density can not be simultaneously brought into agreement with the experimental results without invoking novel mechanisms suppressing Stark mixing in the (Heμ) L-shell. © 1989.
• Soff, G., & Rafelski, J. (1989). Radiative muon capture in light atoms. Zeitschrift für Physik D Atoms, Molecules and Clusters, 14(3), 187-190.
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  Abstract: Total cross sections for radiative muon capture into inner shells of light atoms are evaluated. © 1989 Springer-Verlag.
• Jandel, M., Danos, M., & Rafelski, J. (1988). Active target production of muons for muon-catalyzed fusion. Physical Review C, 37(1), 403-406.
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  Abstract: Using a Monte Carlo method, we study the energy efficiency of muon production by a high-energy beam of deuterons, i.e., protons and neutrons, injected into infinite deuterium-tritium targets. We present detailed results for the dependence on target density and beam energy. The key role of secondary (shower) production of muons is demonstrated. Constraints on the possibility of muon catalyzed fusion power reactors are established. © 1988 The American Physical Society.
• Rafelski, J. (1988). QUARK-GLUON PLASMA IN 4 GEV/C ANTIPROTON ANNIHILATIONS ON NUCLEI. PHYSICS LETTERS B, 207(4), 371-376.
• Rafelski, J. (1988). Quark-gluon plasma in 4 GeV/c antiproton annihilations on nuclei. Physics Letters B, 207(4), 371-376.
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  Abstract: Recent data on strange particle production in 4 GeV/c antiproton annihilations on Ta can be successfully interpreted if quark-gluon plasma formation is assumed along with a simple reaction model in which antiprotons deposit energy in the forward cone of nuclear matter within the target nucleus. The observed spectra and total abundances of lambdas and kaons are consistent with the hypothesis that (super cooled) quark matter phase has been formed at a rather modest temperature T≲60 MeV. The spectra can then be successfully interpreted both with reference to their form and relative abundance. © 1988.
• Rafelski, J., & Schnabel, A. (1988). Quark-gluon plasma in nuclear collisions at 200 GeV/A. Physics Letters B, 207(1), 6-10.
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  Abstract: Assuming complete inelasticity of nuclear collisions at 200 GeV/A we consider the properties of the arising high temperature and density nuclear matter fireball. Pion multiplicity and particle rapidity distribution can be estimated and correlated with other properties of the fireball. Consistency of the fireball reaction picture with the quark-gluon plasma structure is shown. © 1988.
• Danos, M., M̈ller, B., & Rafelski, J. (1987). Comment on Muonalpha-particle sticking probability in muon-catalyzed fusion. Physical Review A, 35(6), 2741-2743.
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  Abstract: Céperley and Alder recently reported [Phys. Rev. A 31, 1999 (1985)] a calculation of the muon sticking probability using three-body Coulomb wave functions of the dt muomolecule. We comment here that such calculations require in addition the incorporation of the interplay of the nuclear reaction dynamics with the Coulomb problem. © 1987 The American Physical Society.
• Jacob, M., & Rafelski, J. (1987). Longitudinal Λ polarization, Ξ abundance and quark-gluon plasma formation. Physics Letters B, 190(1-2), 173-176.
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  Abstract: The relatively large abundance of Ξ expected to be a peculiar feature for the quark-gluon plasma formed in relativistic nuclear collisions can be readily observed by measuring the longitudinal polarization of Λ into which Ξ cascades.This characteristics Ξ-signature of the quark-gluon plasma is discussed. © 1987.
• Nakano, K., & Rafelski, J. (1987). Conventional nuclear European Muon Collaboration effect in deep inelastic lepton-nucleus scattering. Physical Review C, 36(4), 1497-1503.
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  Abstract: The influence of the conventional nuclear structure on the European Muon Collaboration effect is critically reviewed. The ratio of deep inelastic lepton nucleon to lepton nucleus cross sections is shown to be sensitively dependent on the proper kinematics of the Fermi motion and the careful treatment of the binding effect of nucleons in nuclei. We systematically consider the example Ca40 at -Q2=20 (GeV/c)2. © 1987 The American Physical Society.
• RAFELSKI, J., & DANOS, M. (1987). POSSIBLE SIGNATURE FOR AND EARLY HADRONIZATION MECHANISMS OF QUARK-GLUON PLASMA. PHYSICS LETTERS B, 192(3-4), 432-436.
• RAFELSKI, J., & JONES, S. E. (1987). COLD NUCLEAR-FUSION. SCIENTIFIC AMERICAN, 257(1), 84-&.
• Rafelski, J. (1987). REDISTRIBUTION OF STRANGENESS BETWEEN QUARK GLUON PLASMA AND HADRONIC GAS. PHYSICS LETTERS B, 190(1-2), 167-172.
• Rafelski, J. (1987). Redistribution of strangeness between quark-gluon plasma and hadronic gas. Physics Letters B, 190(1-2), 167-172.
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  Abstract: In a baryon-rich hadronic gas s-quarks, unlike antistrange quarks, can be found in baryonic degrees of freedom. This abundance asymmetry induces an associated asymmetry in the otherwise symmetric quark-gluon plasma section of the fireball volume. The magnitude of this effect is established as a function of thermodynamic variables and experimental consequences are explored. © 1987.
• Rafelski, J., & Danos, M. (1987). Possible signature for and early hadronization mechanisms of quark-gluon plasma. Physics Letters B, 192(3-4), 432-436.
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  Abstract: We consider the ratio of particle abundances radiated from quark-gluon plasma above mean thermal energy and point out signigicant differences expected as compared with global particle yields. Two microscopic processes leading to medium to high E⊥ abundances are quantitatively considered and the means of determining the plasma baryochemical potential are discussed. Strong anomalies in strange antibaryon spectra are found, characteristic of the formation of quark-gluon plasma. © 1987.
• Rafelski, J., & Jones, S. E. (1987). COLD NUCLEAR FUSION.. Scientific American, 257(1), 84-89.
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  Abstract: The electronlike particles called muons can catalyze nuclear fusion reactions, eliminating the need for powerful lasers or high-temperature plasmas. The process may one day become a commercial energy source.
• Tupper, G., Danos, M., Müller, B., & Rafelski, J. (1987). On the detection of cosmic-background neutrinos by acoustic phonon scattering. Physical Review D, 35(1), 394-396.
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  Abstract: We examine the possible detection of cosmic-background neutrinos by coherent neutrino-phonon scattering. Our conclusion is that at least for simple detector schemes the reaction rate is unobservably small. © 1987 The American Physical Society.
• Bondorf, J., Garrett, J. D., Gregoire, C., Gutbrod, H., Morrison, G. C., Nagamiya, S., & Rafelski, J. (1986). Conference panel. Nuclear Physics, Section A, 447(C), 655-700.
• Clark, J. W., Cleymans, J., & Rafelski, J. (1986). Clustered quark matter. Physical Review C, 33(2), 703-708.
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  Abstract: In cold quark matter, quantum chromodynamic binding effects can favor clustering of three quarks into nucleon-like clusters. An equation of state of clustered quark matter is derived. It is estimated that the adiabatic transformation of nuclear matter to clustered quark matter sets in at about 1 baryon/fm3, while at the minimum of the energy per baryon the excitation energy relative to ordinary nuclear matter is only 200 MeV/b. © 1986 The American Physical Society.
• Danos, M., M̈ller, B., & Rafelski, J. (1986). Detuning reduction of muon sticking in resonant muon-catalyzed d-t fusion. Physical Review A, 34(5), 3642-3645.
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  Abstract: The nuclear fusion reaction in the (dt)+ molecule is affected by the presence of the muon in the relatively loosely bound mesomolecular orbit. Due to the sharing of the available energy between the muon and the nuclei in the final state, a muon attached to the recoiling particle reduces the energy available to the nuclear fusion reaction by about 9050 keV and thus detunes the resonant d-t reaction amplitude by an important factor. © 1986 The American Physical Society.
• KOCH, P., MULLER, B., & RAFELSKI, J. (1986). STRANGENESS IN RELATIVISTIC HEAVY-ION COLLISIONS. PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS, 142(4), 167-262.
• KOCH, P., MULLER, B., & RAFELSKI, J. (1986). STRANGENESS PRODUCTION AND EVOLUTION IN QUARK GLUON PLASMA. ZEITSCHRIFT FUR PHYSIK A-HADRONS AND NUCLEI, 324(4), 453-463.
• Koch, P., Müller, B., & Rafelski, J. (1986). Strangeness in relativistic heavy ion collisions. Physics Reports, 142(4), 167-262.
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  Abstract: Abundances of strange antibaryons formed in nuclear collisions at above 10 GeV/A are considered as a most accessible diagnostic tool for the study of the possible formation and physical properties of the quark-gluon plasma phase of hadronic matter. In this report we describe the current status and develop a dynamical approach in order to describe strange particle formation in nuclear collisions at high energy. © 1986.
• Koch, P., Müller, B., & Rafelski, J. (1986). Strangeness production and evolution in quark gluon plasma. Zeitschrift für Physik A Atomic Nuclei, 324(4), 453-463.
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  Abstract: The formation and evolution of strange quarks in quark gluon plasma is studied assuming perturbative QCD and qualitative models of plasma phase expansion. Chemical equilibrium abundance characteristic of the hottest and densest phase of nuclear collisions is proven to survive the process of expansion and cooling of the plasma. © 1986 Springer-Verlag.
• Müller, B., & Rafelski, J. (1986). Production of light pseudoscalar particles in heavy-ion collisions. Physical Review D, 34(9), 2896-2899.
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  Abstract: We calculate the cross section for the production of a hypothetical light neutral pseudoscalar particle in heavy-ion collisions due to the two-photon process. For an inverse coupling strength f in the 100-GeV range we predict a cross section of 10-14 fm2 for production of a particle with 1.5-MeV mass. For the maximal allowed coupling f=5 MeV and an effective reduction of the particle mass due to binding the cross section may reach in to the b range. © 1986 The American Physical Society.
• Rafelski, J. (1986). CORRECTION. PHYSICAL REVIEW LETTERS, 56(21), 2334-2334.
• Rafelski, J., & Mller, B. (1986). Erratum:Strangeness Production in the Quark-Gluon Plasma (Physical Review Letters). Physical Review Letters, 56(21), 2334-.
• STAADT, G., GREINER, W., & RAFELSKI, J. (1986). PHOTONS FROM STRANGE-QUARK ANNIHILATION IN A QUARK-GLUON PLASMA. PHYSICAL REVIEW D, 33(1), 66-71.
• Staadt, G., Greiner, W., & Rafelski, J. (1986). Photons from strange-quark annihilation in a quark-gluon plasma. Physical Review D, 33(1), 66-71.
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  Abstract: We compute the energy spectrum of photons which originate from the quark-annihilation process ssg in quark-gluon plasma. The spectrum peaks at an energy Ema x2ms 400 MeV in the rest frame of the plasma. We expect one photon from the above process in the energy range of 2ms 0.25ms per hundred quark-gluon plasmas of a size R=3 fm and a lifetime 6 fm/c formed in nuclear collisions. © 1986 The American Physical Society.
• CLARK, J. W., RAFELSKI, J., & WINSTON, J. V. (1985). BRAIN WITHOUT MIND - COMPUTER-SIMULATION OF NEURAL NETWORKS WITH MODIFIABLE NEURONAL INTERACTIONS. PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS, 123(4), 215-273.
• Clark, J. W., Rafelski, J., & Winston, J. V. (1985). Brain without mind: Computer simulation of neural networks with modifiable neuronal interactions. Physics Reports, 123(4), 215-273.
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  Abstract: Aspects of brain function are examined in terms of a nonlinear dynamical system of highly interconnected neuron-like binary decision elements. The model neurons operate synchronously in discrete time, according to deterministic or probabilistic equations of motion. Plasticity of the nervous system, which underlies such cognitive collective phenomena as adaptive development, learning, and memory, is represented by temporal modification of interneuronal connection strengths depending on momentary or recent neural activity. A formal basis is presented for the construction of local plasticity algorithms, or connection-modification routines, spanning a large class. To build an intuitive understanding of the behavior of discrete-time network models, extensive computer simulations have been carried out (a) for nets with fixed, quasirandom connectivity and (b) for nets with connections that evolve under one or another choice of plasticity algorithm. From the former experiments, insights are gained concerning the spontaneous emergence of order in the form of cyclic modes of neuronal activity. In the course of the latter experiments, a simple plasticity routine ("brainwashing," or "anti-learning") was identified which, applied to nets with initially quasirandom connectivity, creates model networks which provide more felicitous starting points for computer experiments on the engramming of content-addressable memories and on learning more generally. The potential relevance of this algorithm to developmental neurobiology and to sleep states is discussed. The model considered is at the same time a synthesis of earlier synchronous neural-network models and an elaboration upon them; accordingly, the present article offers both a focused review of the dynamical properties of such systems and a selection of new findings derived from computer simulation. © 1985.
• DERRETH, C., GREINER, W., ELZE, H. T., & RAFELSKI, J. (1985). STRANGENESS ABUNDANCES IN PBAR-NUCLEUS ANNIHILATIONS. PHYSICAL REVIEW C, 31(4), 1360-1364.
• Derreth, C., Greiner, W., Elze, H., & Rafelski, J. (1985). Strangeness abundances in p»-nucleus annihilations. Physical Review C, 31(4), 1360-1364.
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  Abstract: Strange particle abundances in small volumes of hot hadronic gas are determined in the canonical ensemble with exact strangeness and baryon number conservation. Substantial density and baryon number dependence is found. A p»d experiment is examined and applications to p»-nucleus annihilations are considered. © 1985 The American Physical Society.
• GLENDENNING, N. K., & RAFELSKI, J. (1985). KAONS AND QUARK-GLUON PLASMA. PHYSICAL REVIEW C, 31(3), 823-827.
• Glendenning, N. K., & Rafelski, J. (1985). Kaons and quark-gluon plasma. Physical Review C, 31(3), 823-827.
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  Abstract: The relative multiplicity abundance K+/π+ and K+/p+ arising in quark-gluon plasma formed in high energy nuclear collisions is determined. It is shown how these ratios assist in discriminating between various reaction channels. © 1985 The American Physical Society.
• KOCH, P., & RAFELSKI, J. (1985). TIME EVOLUTION OF STRANGE-PARTICLE DENSITIES IN HOT HADRONIC MATTER. NUCLEAR PHYSICS A, 444(4), 678-691.
• Kauffmann, S. K., & Rafelski, J. (1985). Resonant-exchange mechanism: Limitations to its effectiveness. Physical Review D, 31(5), 1149-1150.
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  Abstract: We reexamine the conditions under which the resonant-exchange mechanism proposed by Watson can be expected to lead to a first-order rate for the neutrino-mediated transmutation of H3 and He3 atoms into each other. In the course of this, we are able to formulate rather general criteria for when such ''fragile'' first-order resonance rates, in fact, deteriorate into more familiar second-order ones. © 1985 The American Physical Society.
• Koch, P., & Rafelski, J. (1985). Time evolution of strange-particle densities in hot hadronic matter. Nuclear Physics, Section A, 444(4), 678-691.
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  Abstract: The kinetic equations for production in hot nuclear matter of rare, strange antibaryons are studied numerically. Strange antibaryons are confirmed as viable characteristic signatures of the quark-gluon plasma. We find four orders of magnitude enhancement in the abundance of Ω multiply-strange antibaryons. Strange antibaryon production in the hadronic gas phase is shown to have a relatively slow characteristic time constant of ∼ 10-21 sec to be compared with the 100 times faster equilibration in quark-gluon plasma. © 1985.
• RAFELSKI, J., & MULLER, B. (1985). MUON STICKING IN MUON CATALYZED DOORWAY D-T FUSION. PHYSICS LETTERS B, 164(4-6), 223-227.
• Rafelski, J. (1985). APPARENT MUON LOSS IN MUON CATALYZED FUSION.. Fusion Technology, 8(3), 2727-2730.
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  Abstract: Muon loss to side cycles of muon catalyzed fusion is discussed in a schematic model. Experimentally extracted values for permanent muon loss probability ('muon sticking') depend on the presence of cycles terminating by formation of unobservable low-energy neutrons.
• Rafelski, J., & Müller, B. (1985). Muon sticking in muon catalysed doorway D-T fusion. Physics Letters B, 164(4-6), 223-227.
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  Abstract: Loss of muons due to capture (sticking) by the α-particle formed in a muon catalysed D-T fusion process driven by the intermediate nuclear resonant state in 5He( 3 2+) is investigated. Depending on the properties of the resonant doorway state, the muon sticking probability can be somewhat greater or significantly smaller than the value ≲1% obtained under the hypothesis that the nuclear D-T interaction is independent of relative momentum. © 1985.
• AERTS, A., & RAFELSKI, J. (1984). QCD, BAGS, AND HADRON MASSES. PHYSICS LETTERS B, 148(4-5), 337-342.
• Aerts, A. T., & Rafelski, J. (1984). QCD, bags, and hadron masses. Physics Letters B, 148(4-5), 337-342.
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  Abstract: Hadronic mass spectra are systematically fitted to a QCD and bag motivated expression in which the quark interaction matrix elements are allowed to assume best values. A statistically significant fit is found with B 1 4 ≈ 170 MeV. The inclusion of surface energy σ has been studied and we have found a second, equally significant fit with B 1 4 ≈ 210 MeV and σ ≈ 40 MeV/fm2. However, the corresponding hadrons are unacceptably small, i.e. R ≈ 0.5 fm. Selected strange multiquark states are recomputed and found to have generally a higher mass than currently believed. © 1984.
• Clark, J. W., Winston, J. V., & Rafelski, J. (1984). Self-organization of neural networks. Physics Letters A, 102(4), 207-211.
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  Abstract: The plastic development of a neural-network model operating autonomously in discrete time is described by the temporal modification of interneuronal coupling strengths according to momentary neural activity. A simple algorithm ("brainwashing") is found which, applied to nets with initially quasirandom connectivity, leads to model networks with properties conductive to the simulation of memory and learning phenomena. © 1984.
• ELZE, H. T., GREINER, W., & RAFELSKI, J. (1984). COLOR DEGREES OF FREEDOM IN A QUARK GLUE PLASMA AT FINITE BARYON DENSITY. ZEITSCHRIFT FUR PHYSIK C-PARTICLES AND FIELDS, 24(3-4), 361-365.
• Elze, H., Greiner, W., & Rafelski, J. (1984). Color degrees of freedom in a quark-glue plasma at finite baryon density. Zeitschrift für Physik C: Particles and Fields, 24(3), 361-365.
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  Abstract: We derive the color-singlet partition function for a quark-glue plasma with finite quark (baryon number) density by a projection method. Due to colorlessness there is a gradual "freezing" (reduction) of internal degrees of freedom as compared to the Stefan-Boltzmann limit. We find here that this non-perturbative effect is reduced by a finite quark density. A relation between the requirement of colorlessness of all physical states and QCD is proposed. © 1984 Springer-Verlag.
• Greiner, W., Koch, P., & Rafelski, J. (1984). Strange particle production in pp and pN reactions. Physics Letters B, 145(1-2), 142-146.
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  Abstract: A statistical model of particle production valid for a wide range of Feynman x is developed and applied to describe strange particle production in hadronic collisions. Predictions of relative abundances of multiply strange hadrons are made which compare well with the available fragmentary data. © 1984.
• KARL, G., MILLER, G. A., & RAFELSKI, J. (1984). NUCLEON MAGNETIC-MOMENTS IN NUCLEI AND QUARK DEGREES OF FREEDOM. PHYSICS LETTERS B, 143(4-6), 326-328.
• Karl, G., Miller, G. A., & Rafelski, J. (1984). Nucleon magnetic moments in nuclei and quark degrees of freedom. Physics Letters B, 143(4-6), 326-328.
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  Abstract: We discuss the values of the magnetic moments of nucleons when inside a nucleus and present evidence that shows these moments to be larger than in free space. We present a possible theoretical explanation in the special case of the trinucleon system in terms of the quark structure of nucleons. © 1984.
• Kauffmann, S. K., & Rafelski, J. (1984). Analytic study of a sequence of path integral approximations for simple quantum systems at low temperature. Zeitschrift für Physik C Particles and Fields, 24(2), 157-162.
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  Abstract: The sequence of Feynman-Trotter approximations to the thermal Feynman path integral for the simple harmonic oscillator is obtained in an easily analyzable closed form. While it converges pointwise at every non-zero temperature to the quantum thermal propagator, the sequence manifests a highly non-uniform behaviour in the zero temperature limit-every one of its elements tends toward the classical ground state (static equilibrium). For high order elements of the sequence, there is an abrupt "collapse" from the quantum to the classical ground state with falling temperature, a phenomenon which bears a possibly misleading resemblance to a phase transition. It is shown that Feynman-Trotter sequences for many simple systems other than the harmonic oscillator also have all their elements tending to the classical static equilibrium state in the zero temperature limit. © 1984 Springer-Verlag.
• Rafelski, J. (1984). STRANGENESS PRODUCTION IN THE QUARK GLUON PLASMA. NUCLEAR PHYSICS A, 418(APR), C215-C235.
• Rafelski, J. (1984). Strangeness production in the quark gluon plasma. Nuclear Physics, Section A, 418(C), 215-235.
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  Abstract: It is shown that perturbative QCD predicts abundant strange quark production in the plasma created in high energy nuclear collisions. Considering further the strange particle production in the hadronic gas phase, I show that the strangeness abundance in the plasma is 10-50 times higher as compared with the gas phase in similar thermodynamic conditions. Possible experiments leading to the identification of the plasma phase are described. © 1984.
• DANOS, M., & RAFELSKI, J. (1983). PARTICLE RADIATION BY HOT QUARK-GLUON PLASMA. PHYSICAL REVIEW D, 27(3), 671-674.
• Danos, M., & Rafelski, J. (1983). Particle radiation by hot quark-gluon plasma. Physical Review D, 27(3), 671-674.
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  Abstract: Highly excited hadronic matter consisting of quarks and gluons radiates an important fraction of its excitation energy by hadron emission. This relieves the surface pressure and reduces the importance of the expansion to the cooling of the plasma. Qualitative model calculations are presented. © 1983 The American Physical Society.
• ELZE, H. T., GREINER, W., & RAFELSKI, J. (1983). ON THE COLOR-SINGLET QUARK-GLUE PLASMA. PHYSICS LETTERS B, 124(6), 515-519.
• Elze, H., Greiner, W., & Rafelski, J. (1983). On the color-singlet quark-glue plasma. Physics Letters B, 124(6), 515-519.
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  Abstract: The assumed color-singlet character of physical states is treated exactly in a canonical partition function for the quark-glue plasma in a finite volume. It is shown that this non-perturbative effect leads to a gradual "freezing" of internal degrees of freedom as compared to the Stephan-Boltzmann limit. © 1983.
• KOCH, P., RAFELSKI, J., & GREINER, W. (1983). STRANGE HADRONS IN HOT NUCLEAR-MATTER. PHYSICS LETTERS B, 123(3-4), 151-154.
• Koch, P., Rafelski, J., & Greiner, W. (1983). Strange hadrons in hot nuclear matter. Physics Letters B, 123(3-4), 151-154.
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  Abstract: We compute relative abundances of strange hadronic particles produced in highly excited nuclear matter as functions of temperature and baryo-chemical potential. Quantitative predictions are made for the particle multiplicity ratios: 〈nK+〉/〈nK-〉, 〈nK+〉/〈nΛ〉, 〈nK-〉/ 〈nΛ〉, 〈nΛ〉/〈nΛ-〉 Possible measurements of baryo-chemical potential is described. Our results are quantitatively compatible with present experimental data obtained in nuclear collisions. © 1983.
• Schäfer, A., Rafelski, J., & Greiner, W. (1983). A five-dimensional Dirac-theory and its relation to nonlocal theories in four dimensions. Annals of Physics, 147(2), 445-459.
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  Abstract: A generalization of the Dirac-theory to one time- and four space-like coordinates is discussed. The consequences of discretizing the fifth dimension are studied and a relationship with nonlocal four dimensional field-theory is found. © 1983.
• Hagedorn, R., & Rafelski, J. (1982). Analytic structure and explicit solution of an important implicit equation. Communications in Mathematical Physics, 83(4), 563-578.
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  Abstract: The equation z=2 G(z)-exp G(z)+1 (and similar ones obtained from it by substitutions) appears in connection with a variety of problems ranging from pure mathematics (combinatorics; some first order, nonlinear differential equations) over statistical thermodynamics to renormalization theory. It is therefore of interest to solve this equation for G(z) explicitly. It turns out, after study of the complex structure of the z and G planes, that an explicit integral representation of G(z) can be given, which may be directly used for numerical calculations of high precision. © 1982 Springer-Verlag.
• MULLER, B., & RAFELSKI, J. (1982). ROLE OF INTERNAL SYMMETRY IN PPBAR ANNIHILATION. PHYSICS LETTERS B, 116(4), 274-278.
• Müller, B., & Rafelski, J. (1982). Role of internal symmetry in pp annihilation. Physics Letters B, 116(4), 274-278.
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  Abstract: Internal symmetry influences the form of quantum spectra as well as the abundance of particles emitted by a thermal source. Isospin conservation in proton-antiproton annihilation is used to quantitatively illustrate the influence of these phenomena on mean pion multiplicities and the apparent primary pion temperature parameter. © 1982.
• M̈ller, B., & Rafelski, J. (1982). Self-consistent gluon screening of a strong SU(2) source. Physical Review D, 25(2), 566-572.
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  Abstract: We construct a variational condensate ground state for the SU(2) gauge field in the presence of an external source and present the numerical solution for a particular example. © 1982 The American Physical Society.
• RAFELSKI, J., & MULLER, B. (1982). STRANGENESS PRODUCTION IN THE QUARK-GLUON PLASMA. PHYSICAL REVIEW LETTERS, 48(16), 1066-1069.
• Rafelski, J. (1982). Extreme states of nuclear matter. Nuclear Physics, Section A, 374(C), 489-502.
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  Abstract: A theoretical description of highly excited nuclear matter is presented. Two physically different domains are treated: the hadronic gas phase in which individual nucleons and mesons coexist as separate entities,and that consisting of one large hadronic cluster of quarks and gluons. Possible characteristic observable phenomena of the quark plasma are considered. © 1982.
• Rafelski, J., & Müller, B. (1982). Strangeness production in the quark-gluon plasma. Physical Review Letters, 48(16), 1066-1069.
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  Abstract: Rates are calculated for the processes gg→ss̄ and uū,dd̄→ss̄ in highly excited quarkgluon plasma. For temperature T>~160 MeV the strangeness abundance saturates during the lifetime (∼10-23 sec) of the plasma created in high-energy nuclear collisions. The chemical equilibration time for gluons and light quarks is found to be less than 10-24 sec. © 1982 The American Physical Society.
• Klein, A., Rafelski, H., & Rafelski, J. (1981). IBM hamiltonian, Bohr collective hamiltonian and classical limit for an exactly soluble model with the symmetry of O(5). Nuclear Physics, Section A, 355(1), 189-206.
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  Abstract: Interacting boson model (IBM), Bohr collective hamiltonian and adiabatic collective model descriptions are derived from a shell model (describing pairing plus two-dimensional quadrupole-quadrupole interactions) with the symmetry of the Lie algebra O(5). The tools utilized for these purposes are three boson mappings from the fermion pair space, two exact and one approximate. Adiabatic descriptions are derived by two distinct methods. The extension of the methods of this paper to more realistic models is outlined. © 1981.
• MULLER, B., & RAFELSKI, J. (1981). TEMPERATURE-DEPENDENCE OF THE BAG CONSTANT AND THE EFFECTIVE LAGRANGIAN FOR GAUGE-FIELDS AT FINITE TEMPERATURES. PHYSICS LETTERS B, 101(1-2), 111-118.
• Müller, B., & Rafelski, J. (1981). Temperature dependence of the bag constant and the effective lagrangian for gauge fields at finite temperatures. Physics Letters B, 101(1-2), 111-118.
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  Abstract: We calculate the free energy for a gauge field at finite temperature in the presence of a constant gauge magnetic field in the one-loop approximation, omitting unstable modes. The effect of finite temperature on the approximate "true" Savvidy ground state of QCD is derived. A phase transition to the perturbative ground state at Tcr=1.5Bs 1 4 ≈210 MeV is found. © 1981.
• Rafelski, J., & Gross, E. K. (1981). Rebuttal to the "comment on Electromagnetic potential in Thomas-Fermi-Dirac atoms". Physical Review A, 23(4), 2087-.
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  Abstract: The cancellation of the exchange and relativistic corrections to the energies of inner shells in heavy atoms is discussed. © 1981 The American Physical Society.
• Schmidt, G., Elze, H., & Rafelski, J. (1981). Mass limits for non-degenerate white dwarfs. Nuclear Physics, Section A, 364(2-3), 527-532.
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  Abstract: We obtain the dependence of the upper mass limit of white dwarf stars on the specific entropy per electron. For non-degenerate stars significantly larger masses are found. Stellar collapse as an entropy-producing process can therefore have a self-stabilizing influence on the stellar evolution. © 1981.
• ELZE, H. T., GREINER, W., & RAFELSKI, J. (1980). THE RELATIVISTIC IDEAL FERMI GAS REVISITED. JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS, 6(9), L149-L153.
• Elze, H. -., Greiner, W., & Rafelski, J. (1980). The relativistic ideal Fermi gas revisited. Journal of Physics G: Nuclear Physics, 6(9), L149-L153.
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  Abstract: The thermodynamic potential of the ideal Fermi gas is evaluated analytically for arbitrary temperatures and chemical potentials in the case that the latter is much larger than the rest mass of the particles. This is achieved by allowing for the necessary particle-antiparticle chemical equilibrium. As a first application the authors consider the properties of hot quark matter in a giant MIT bag.
• HAGEDORN, R., & RAFELSKI, J. (1980). HOT HADRONIC MATTER AND NUCLEAR COLLISIONS. PHYSICS LETTERS B, 97(1), 136-142.
• RAFELSKI, J., & DANOS, M. (1980). THE IMPORTANCE OF THE REACTION VOLUME IN HADRONIC COLLISIONS. PHYSICS LETTERS B, 97(2), 279-282.
• Rafelski, J. (1980). PBAR ANNIHILATION ON HEAVY-NUCLEI. PHYSICS LETTERS B, 91(2), 281-284.
• Rafelski, J. (1980). p annihilation on heavy nuclei. Physics Letters B, 91(2), 281-284.
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  Abstract: In order to study the properties of nuclear matter at high temperature and/or density, a substantial amount of energy has to be delivered to a heavy nucleus. In this paper we propose employing the annihilation of antiprotons at LEAR momenta of 0.5-1.5 GeV/c on heavy nuclei; a qualitative discussion of possible interesting reaction channels is presented. © 1980.
• Rafelski, J., & Danos, M. (1980). The importance of the reaction volume in hadronic collisions. Physics Letters B, 97(2), 279-282.
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  Abstract: The pair production in the thermodynamic model is shown to depend sensitively on the (hadronic) reaction volume. Strangeness production in nucleus-nucleus collisions is treated as an example. © 1980.
• Danos, M., & Rafelski, J. (1979). S{cyrillic}i{cyrillic}n{cyrillic}g{cyrillic}u{cyrillic}l{cyrillic}ya{cyrillic}r{cyrillic}n{cyrillic}o{cyrillic}s{cyrillic}t{cyrillic}i{cyrillic} v{cyrillic} k{cyrillic}v{cyrillic}a{cyrillic}n{cyrillic}t{cyrillic}o{cyrillic}v{cyrillic}o{cyrillic}i{cyrillic, short} t{cyrillic}ye{cyrillic}o{cyrillic}r{cyrillic}i{cyrillic}i{cyrillic} p{cyrillic}o{cyrillic}l{cyrillic}ya{cyrillic}. Il Nuovo Cimento A, 49(3), 326-367.
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  Abstract: The short-range behaviour of certain Feynman integrals reveals mathematical properties which are not those of either functions or distributions-they contain terms which are more singular than distributions and possess inherent ambiguities. Two classes of singularities exist: To the first one belong all those singularities which have a physical meaning in the sense that in a convergent (regularized) quantum field theory they contribute to observable quantities, frequently as renormalization constants. Most of the singularities of the second, the spurious type, violate the symmetries of the Lagrangian. We demonstrate that they are associated with certain mathematical difficulties of unregularized theories. Much of our analysis deals with the isolation of singularities of this type and with the study of the properties of the singular products of distribution. We argue that the four-dimensional integration leading to the S-matrix in the perturbation expansion must be carried out over an open domain which leaves out the contributions from singularities of the contact type, that is terms proportional to δ4x-y. © 1979 Società Italiana di Fisica.
• Gross, E. K., & Rafelski, J. (1979). Electromagnetic potential in Thomas-Fermi-Dirac atoms. Physical Review A, 20(1), 44-47.
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  Abstract: The authors discuss the relativistic Thomas-Fermi model for atoms and derive a relativistic extension of the Dirac exchange term. As a result of this model the mutual cancellation of the exchange and relativistic corrections to the energies of inner-shell electrons in heavy atoms (Z>50) is demonstrated. © 1979 The American Physical Society.
• Bell, J., Davis, A., & Rafelski, J. (1978). Partons of a spherical box. Physics Letters B, 78(1), 67-70.
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  Abstract: Calculation of parton distributions in the "cavity approximation" to the MIT bag model gives a divergent sum of positive terms. This suggests that Bjorken scaling does not hold for the deep inelastic scattering does not hold for the deep inelastic scattering in this version of the model. © 1978.
• Danos, M., & Rafelski, J. (1978). Higher-order effects in Fermi-type charged current theory of weak interactions: Semi-leptonic neutral currents. Physics Letters B, 73(3), 313-316.
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  Abstract: In a convergent field theory rescattering graphs lead to neutral-current effects of the observed magnitude if the effective cut-off momentum is ∼G- 1 2 ≈ 300 GeV. A perturbation expansion is justified owing to the value f=0.18 of the resulting expansion parameter. © 1978.
• Klein, A., & Rafelski, J. (1978). Bose condensation in supercritical external fields charged condensates. Zeitschrift für Physik A Atoms and Nuclei, 284(1), 71-81.
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  Abstract: This paper extends a previous one which was applicable only to short range interactions. We study the relativistic field theory of a charged spin-zero boson field in the presence of the Coulomb field of a prescribed (nuclear) charge distribution. It is shown that for a sufficiently intense field the ground state is unstable against the formation of a Bose-Einstein condensate of negatively charged bosons, positively charged bosons escaping the system. When the effects of weak interaction are included, the instability occurs in a weaker field and positrons are emitted. A consistent quantum theory is formulated after the Coulomb interaction of the bosons is included. Properties of the condensate are examined in the limit of large condensate density, in a mean field approximation, which is also studied numerically. Possible implications concerning the existence of abnormally bound nuclei are presented. © 1978 Springer-Verlag.
• RAFELSKI, J., FULCHER, L. P., & KLEIN, A. (1978). FERMIONS AND BOSONS INTERACTING WITH ARBITRARILY STRONG EXTERNAL FIELDS. PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS, 38(5), 227-361.
• RAFELSKI, J., MULLER, B., & GREINER, W. (1978). SPONTANEOUS VACUUM DECAY OF SUPERCRITICAL NUCLEAR COMPOSITES. ZEITSCHRIFT FUR PHYSIK A-HADRONS AND NUCLEI, 285(1), 49-52.
• Rafelski, J. (1978). Supercritical fields and dynamic confinement. Physics Letters B, 79(4-5), 419-422.
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  Abstract: The mechanism leading to the dynamic confinement of heavy fermions for strong coupling constants in quantum electrodynamics of two charged light and heavy fermion fields is described. © 1978.
• Rafelski, J., Fulcher, L. P., & Klein, A. (1978). Fermions and bosons interacting with arbitrarily strong external fields. Physics Reports, 38(5), 227-361.
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  Abstract: The question, "What happens to the electron orbitals as the charge of the nucleus is increased without bounds?" has inspired much of the interest in the description of particles bound strongly by external fields. Interest in this problem and in the related Klein paradox extends back nearly to the beginnings of relativistic quantum mechanics. However, the correct interpretation of the theory for overcritical potentials, where the parts of the complete set of single particle solutions associated with particles and antiparticles are no longer distinct, was given only recently. The understanding of the spectrum of the Dirac and Klein-Gordon equations is essential in order to obtain an appropriate physical description with quantum field theory. The strong binding by more than twice the rest mass of the particles in overcritical external potentials leads to qualitatively new effects. In the case of fermions we find spontaneous positron emission accompanied by creation of a charged lowest energy state, i.e. a charged vacuum. The number of positrons produced spontaneously is limited by the Pauli exclusion principle. For bosons we find that depending on the character of the external potential, either neutral or charged Bose condensates develop. While the questions associated with the meson fields seem academic at the moment, the effects attributed to the fermion field stand a good chance of being tested in an experiment in the near future. It is expected that in heavy ion collisions such as uranium on uranium near the Coulomb barrier overcritical electromagnetic fields will be created. © 1978.
• Rafelski, J., Müller, B., & Greiner, W. (1978). Spontaneous vacuum decay of supercritical nuclear composites. Zeitschrift für Physik A, 285(1), 49-52.
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  Abstract: We show that in deep inelastic heavy ion collisions with Z1+Z2> 173 the spontaneous decay of the neutral vacuum by emission of positrons may be isolated from other competing positron producing processes. From the details of the spontaneous positron spectrum information about the nature (lifetime, shape and angular momentum) of the composite nuclear system may be derived. © 1978 Springer-Verlag.
• SOFF, G., REINHARDT, J., BETZ, W., & RAFELSKI, J. (1978). SYSTEMATIC INVESTIGATIONS OF BINDING-ENERGIES OF INNER-SHELL ELECTRONS IN SUPERHEAVY QUASIMOLECULES. PHYSICA SCRIPTA, 17(4), 417-419.
• BOGUTA, J., & RAFELSKI, J. (1977). THOMAS-FERMI MODEL OF FINITE NUCLEI. PHYSICS LETTERS B, 71(1), 22-26.
• Boguta, J., & Rafelski, J. (1977). Thomas Fermi model of finite nuclei. Physics Letters B, 71(1), 22-26.
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  Abstract: A relativistic Thomas-Fermi model of finite nuclei is considered. The effective nuclear interaction is mediated by exchanges of isoscalar scalar and vector mesons. We include also a self-interaction of the scalar meson field and the Coulomb repulsion of the protons. The parameters of the model are constrained by the average nuclear properties. The Thomas-fermi equations are solved numerically for finite, stable nuclei. The particular case of 20882Pb is considered in more detail. © 1977.
• Danos, M., & Rafelski, J. (1977). Some consequences of fermi-type theory of weak interactions. Lettere Al Nuovo Cimento Series 2, 19(9), 339-343.
• MULLER, B., GREINER, W., & RAFELSKI, J. (1977). INTERPRETATION OF EXTERNAL FIELDS AS TEMPERATURE. PHYSICS LETTERS A, 63(3), 181-183.
• Müller, B., Greiner, W., & Rafelski, J. (1977). Interpretation of external fields as temperature. Physics Letters A, 63(3), 181-183.
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  Abstract: We show that average excitation of the vacuum state in the presence of an external electric field can be described by an effective temperature kT = eE (2πm). We present a qualitative generalization of our result to other interactions. Some phenomenological implications concerning matter at low temperatures in strong electric fields (105 V/cm) are offered. © 1977.
• Rafelski, J. (1977). Soliton solutions of a selfinteracting dirac field in three space dimensions. Physics Letters B, 66(3), 262-266.
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  Abstract: An (attractive) selfinteraction of the Dirac field is considered in three space dimensions. A virial theorem for the kinetic energy of the field is derived. The properties of the classical fields are studied and soliton solutions developed numerically. The relevance of these solutions to the construction of quark bag models without gluons is discussed. © 1977.
• Rafelski, J. (1977). VIRIAL THEOREM AND STABILITY OF LOCALIZED SOLUTIONS OF RELATIVISTIC CLASSICAL INTERACTING FIELDS. PHYSICAL REVIEW D, 16(6), 1890-1899.
• Rafelski, J. (1977). Virial theorem and stability of localized solutions of relativistic classical interacting fields. Physical Review D, 16(6), 1890-1899.
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  Abstract: The properties of classical meson fields interacting with the Dirac field are considered in more detail analytically. We obtain a virial relation between the kinetic and potential energy of the interacting Dirac field. The stability of the classical solutions of the coupled fields constrained to the lowest particle solution of the Dirac equation in three space dimensions is investigated. A criterion allowing the determination of stability of Abelian meson fields in interaction with the Dirac field is given. © 1977 The American Physical Society.
• RAFELSKI, J., & MULLER, B. (1976). CRITICAL DISTANCE IN COLLISIONS OF HEAVY-IONS. PHYSICS LETTERS B, 65(3), 205-208.
• RAFELSKI, J., & MULLER, B. (1976). MAGNETIC SPLITTING OF QUASIMOLECULAR ELECTRONIC STATES IN STRONG FIELDS. PHYSICAL REVIEW LETTERS, 36(10), 517-520.
• Rafelski, J. (1976). Self-consistent quark bag in three space dimensions. Physical Review D, 14(9), 2358-2361.
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  Abstract: A schematic model of a quark bag with scalar gluons is considered quantitatively in three space dimensions. Stable spherically symmetric solutions of c-number self-consistent bag equations are obtained numerically. The structure constants of hadrons are calculated as functions of the coupling constant and the gluon mass. Good agreement of absolute values of the proton magnetic moment and the bag mass with experiment is found. © 1976 The American Physical Society.
• Rafelski, J. (1976). Soliton solutions in three-space dimensions. Scalar field in interaction with the dirac field. Lettere Al Nuovo Cimento Series 2, 17(17), 575-581.
• Rafelski, J. (1976). Vacuum polarization- and molecular-potential effects in heavy-ion scattering. Physical Review C, 13(5), 2086-2088.
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  Abstract: The corrections to the heavy-ion scattering cross sections due to the presence of perturbing vacuum polarization and molecular potentials are evaluated. We find effects on the cross section up to 0.7% in O16 with Pb208 collisions due to vacuum polarization and up to 2.6% in U with Th collisions due to molecular and vacuum polarization corrections. NUCLEAR REACTIONS Calculations of modifications of elastic heavy-ion σ(θ) due to vacuum polarization and molecular potentials. © 1976 The American Physical Society.
• Rafelski, J., & Müller, B. (1976). The critical distance in collisions of heavy ions. Physics Letters B, 65(3), 205-208.
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  Abstract: There is a large discrepancy in published values of the critical distance in heavy-ion collisions. We have recalculated the critical distance by a more accurate method for symmetric collisions of point nuclei as a function of Z. The reasons for the discrepancy are discussed. © 1976.
• Rafelski, J., & Müller, B. (1976). Vector coupling and bound states of fermions in three space dimensions. Physical Review D, 14(12), 3532-3535.
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  Abstract: The behavior of fermions interacting via vector gluons in the strong-coupling limit is investigated. A suitable coupling between the Dirac and the vector-gluon field gives rise to bound-state solutions. The coherent field approximation is employed to find the bound-state masses, which are further discussed by analytical and numerical methods and are found to be positive-definite in the example considered numerically. © 1976 The American Physical Society.
• Rafelski, J., & M̈ller, B. (1976). Magnetic splitting of quasimolecular electronic states in strong fields. Physical Review Letters, 36(10), 517-520.
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  Abstract: The heavy-ion motion in sub-Coulomb collisions generates extreme magnetic fields. The hyperfine splitting of the spin- quasimolecular electronic states in U + U is found to reach 10% of the molecular binding energy (100 keV). Also Pb+Pb and Xe+Xe collisions are considered. © 1976 The American Physical Society.
• KLEIN, A., & RAFELSKI, J. (1975). BOSE CONDENSATION IN SUPERCRITICAL EXTERNAL FIELDS. PHYSICAL REVIEW D, 11(2), 300-311.
• Klein, A., & Rafelski, J. (1975). Bose condensation in supercritical external fields. Physical Review D, 11(2), 300-311.
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  Abstract: We study the relativistic field theory of a charged spin-zero boson field in the presence of an external field, such as the Coulomb field of a prescribed charge distribution. It is shown that for a sufficiently intense field the ground state is unstable against the formation of a Bose-Einstein condensate of charged boson pairs. A consistent quantum theory can be formulated when known nonlinear couplings such as the Coulomb interactions of the bosons are properly included in the Hamiltonian. Speculations are offered concerning the possible stability of nuclei with charge number Z103. © 1975 The American Physical Society.
• Klein, A., & Rafelski, J. (1975). Comments on "Bose condensation in supercritical external fields". Physical Review D, 12(4), 1194-1195.
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  Abstract: We agree that our previous analysis does not apply to a spinless particle in an external Coulomb field. We explain why it continues to apply in toto for a spinless particle in a short-range external field. We describe in qualitative terms the correct quantization for the Coulomb case, which has not previously appeared in the literature. © 1975 The American Physical Society.
• MULLER, B., & RAFELSKI, J. (1975). STABILIZATION OF CHARGED VACUUM CREATED BY VERY STRONG ELECTRICAL FIELDS IN NUCLEAR-MATTER. PHYSICAL REVIEW LETTERS, 34(6), 349-352.
• Müller, B., & Rafelski, J. (1975). Stabilization of the charged vacuum created by very strong electrical fields in nuclear matter. Physical Review Letters, 34(6), 349-352.
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  Abstract: The expectation value of electrical charge in charged vacuum is calculated utilizing the Thomas-Fermi model. We find almost complete screening of the nuclear charge. For any given nuclear density there is an upper bound for the electrical potential. For normal nuclear densities this value is - 250 MeV. This suggests that the vacuum is stable against spontaneous formation of heavy, charged particles. © 1975 The American Physical Society.
• DANOS, M., GREINER, W., & RAFELSKI, J. (1974). FIELDS NONLOCAL IN CLIFFORD SPACE .1. CLASSICAL GAUGE-INVARIANT NONLINEAR FIELD-THEORY. PHYSICAL REVIEW D, 6(12), 3476-3491.
• Danos, M., & Rafelski, J. (1974). Gauge invariance of the vacuum polarization in quantum electrodynamics. Lettere Al Nuovo Cimento, 10(3), 106-110.
• Klein, A., & Rafelski, J. (1974). On contributions to the pion-nucleus optical potential non-linear in nuclear density: The Ericson-Ericson Lorentz-Lorentz correction. Physics Letters B, 49(4), 318-322.
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  Abstract: A well-defined set of higher order corrections to the lowest order pion-nucleus optical potential is examined within the framework of many-body theory for an infinite nuclear medium. The connection between the pion self-energy operators and multiple scattering formalisms is thereby indicated and a deriviation of the EELL effect given. © 1974.
• MULLER, B., GREINER, W., PEITZ, H., & RAFELSKI, J. (1974). SOLUTION OF DIRAC EQUATION FOR STRONG EXTERNAL FIELDS. PHYSICAL REVIEW LETTERS, 28(19), 1235-&.
• MULLER, B., RAFELSKI, J., & GREINER, W. (1974). AUTOIONIZATION OF POSITRONS IN HEAVY-ION COLLISIONS. ZEITSCHRIFT FUR PHYSIK, 257(3), 183-211.
• Mueller, B., Rafelski, J., & Greiner, W. (1974). Solution of the Dirac equation with two Coulomb centres. NUKLEONIKA, 19(7-8), 741-746.
• PEITZ, H., MULLER, B., RAFELSKI, J., & GREINER, W. (1974). AUTOIONIZATION SPECTRA OF POSITRONS IN HEAVY-ION COLLISIONS. LETTERE AL NUOVO CIMENTO, 8(1), 37-42.
• RAFELSKI, J., FULCHER, L., & GREINER, W. (1974). A CONDITION FOR VANISHING ELECTROMAGNETIC SELF-STRESS IN NONLINEAR CLASSICAL ELECTRODYNAMICS. NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA B, B 7(1), 137-+.
• RAFELSKI, J., FULCHER, L., & GREINER, W. (1974). SUPERHEAVY ELEMENTS AND AN UPPER LIMIT TO ELECTRIC FIELD STRENGTH. PHYSICAL REVIEW LETTERS, 27(14), 958-&.
• Rafelski, J., & Klein, A. (1974). Possible measurement of the vacuum polarization in heavy-ion scattering. Physical Review C, 9(5), 1756-1759.
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  Abstract: A measurement of the vacuum polarization potential in nonrelativistic elastic heavy-ion scattering is suggested. We find that in a typical sub- Coulomb barrier event enough momentum is transferred from the projectile to the target nucleus to make the high-q2 behavior of the photon propagator observable. The elastic cross section is increased in a typical case by 2.5% above the Rutherford value. Only relative measurements are needed. [NUCLEAR REACTIONS Pb208(O16, O16). Calculated vacuum polarization effect, sub-Coulomb, DWBA.] © 1974 The American Physical Society.
• Rafelski, J., Mueller, B., & Greiner, W. (1974). The charged vacuum in overcritical fields. NUKLEONIKA, 19(7-8), 747-765.
• Rafelski, J., Müller, B., & Greiner, W. (1974). The charged vacuum in over-critical fields. Nuclear Physics, Section B, 68(2), 585-604.
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  Abstract: The concept of over-critical fields, i.e. fields in which spontaneous, energy-less electron-position pair creation may occur, is discussed. It is shown that only a charged vacuum can be a stable ground state of the overcritical field. The time-dependent treatment confirms previous results for the cross sections for the auto-ionizing positrons. The questions in connection with the classical Dirac wave functions in over-critical fields are extensively discussed in the frame of the self-consistent formulation of QED including the effects of vacuum polarization and self-energy. © 1974.
• Rafelski, J., Müller, B., Soff, G., & Greiner, W. (1974). Critical discussion of the vacuum polarization measurements in muonic atoms. Annals of Physics, 88(2), 419-453.
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  Abstract: Recent disagreement between theoretical and experimental values of transition energies for outer states in muonic atoms is discussed in the range of 150-440 keV. A brief review of the present status of calculation of the theoretical contributions is given. A rigorous theoretical framework for the electron-muon system is considered. A set of self-consistent equations is derived. Several mechanisms for the explanation of the discrepancy are discussed. No explanation within the frame of standard quantum electrodynamics is found. © 1974.
• DANOS, M., & RAFELSKI, J. (1973). GAUGE-INVARIANCE OF VACUUM POLARIZATION IN QUANTUM ELECTRODYNAMICS. LETTERE AL NUOVO CIMENTO, 10(3), 106-110.
• Danos, M., Greiner, W., & Rafelski, J. (1973). Fields nonlocal in clifford space - II. Quantum theory of interacting fields. Zeitschrift für Physik, 258(2), 147-162.
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  Abstract: A previously proposed field theory is quantized. The theory contains a parameter having the character of an elementary length. We fix the value of this parameter by scaling it to the weak interaction strength. It is shown that this way negative metric states are confined to a region of the order 10-15 cm. The resulting quantum theory of interacting fields is Lorentz and gauge invariant, has a unitary S-matrix, and is convergent. © 1973 Springer-Verlag.
• Kuznetsova, I., & Rafelski, J. (1973). Charmed hadrons from strangeness-rich QGP. JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS, 32(12), S499-S504.
• MULLER, B., RAFELSKI, J., & GREINER, W. (1973). ELECTRON SHELLS IN OVER-CRITICAL EXTERNAL FIELDS. ZEITSCHRIFT FUR PHYSIK, 257(1), 62-77.
• MULLER, B., RAFELSKI, J., & GREINER, W. (1973). ELECTRON WAVE-FUNCTIONS IN OVER-CRITICAL ELECTROSTATIC POTENTIALS. NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA A-NUCLEI PARTICLES AND FIELDS, A 18(3), 551-557.
• MULLER, B., RAFELSKI, J., & GREINER, W. (1973). SOLUTION OF DIRAC EQUATION WITH 2 COULOMB CENTERS. PHYSICS LETTERS B, B 47(1), 5-7.
• Müller, B., Rafelski, J., & Greiner, W. (1973). Electron wave functions in over-critical electrostatic potentials. Il Nuovo Cimento A Series 11, 18(3), 551-573.
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  Abstract: The mathematical properties of the solutions of the Dirac equation in over-critical external potentials are investigated. The 1/r Coulomb potential is treated as the limit R → 0 of cut-off Coulomb potentials (R is the cut-off parameter). The results are interpreted in terms of quantum electrodynamics. A number of new physical phenomena occur in quantum electrodynamics of strong fields. One of the most interesting ones is the autoionization of positrons (energyless creation of electron-positron pairs) in over-critical external fields. © 1973 Società Italiana di Fisica.
• Müller, B., Rafelski, J., & Greiner, W. (1973). Solution of the Dirac equation with two Coulomb centres. Physics Letters B, 47(1), 5-7.
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  Abstract: The Dirac equation for a relativistic particle (electron) in the field of two Coulomb centres Z1 and Z2 - pointlike as well as extended charges - has been solved. The systems BrBr, IAu, UU are shown as examples. © 1973.
• Peitz, H., Müller, B., Rafelski, J., & Greiner, W. (1973). Autoionization spectra of positrons in heavy-ion collisions. Lettere Al Nuovo Cimento Series 2, 8(1), 37-42.
• RAFELSKI, H., & FINK, B. (1973). PARTICLE NUMBER DEPENDENCE OF COLLECTIVE PROPERTIES OF NUCLEI IN RARE-EARTH REGION. ZEITSCHRIFT FUR NATURFORSCHUNG SECTION A-A JOURNAL OF PHYSICAL SCIENCES, A 29(8), 1131-1137.
• RAFELSKI, J., GREINER, W., & MULLER, B. (1973). SUPERHEAVY ELECTRONIC MOLECULES. LETTERE AL NUOVO CIMENTO, 4(11), 469-&.
• Rafelski, J., Greiner, W., & Fulcher, L. (1973). Superheavy elements and nonlinear electrodynamics. Il Nuovo Cimento B Series 11, 13(1), 135-160.
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  Abstract: Maxwell's equations, which underlie electrodynamics, are linear equations. Nonlinear effects, such as photon-photon scattering, are known to arise in quantum electrodynamics, and one might expect them to become important in the case of strong external fields. We investigate the consequences of a class of nonlinear Lagrangians, which includes that of Born and Infeld and whose common property is that they lead to upper limits for the electric-field strength (somewhat analogous to the upper limit for the velocity of a particle in special relativity). These nonlinear Lagrangians also lead to a finite electromagnetic selfenergy for the electron, unlike the case of Maxwellian electrodynamics. The importance of nonlinear effects of course depends upon the size of the upper limit to the electric-field strength. If this upper limit is determined by requiring that the mass of the electron is of an entirely electromagnetic origin, nonlinear effects become very important in determining the eigenvalues of electrons bound to superheavy nuclei. For example, the Is energy eigenvalue is raised by 270 keV for Z= 164. The Lagrangians considered here do not lead to an absolute gap between bound states and the states of the lower continuum; the Iδ energy eigenvalue becomes equal to -0.511 MeV, where the lower continuum begins, for Z=215. An analogy between nonlinear electrodynamics and higherorder vacuum polarization corrections is studied. © 1973 Società Italiana di Fisica.
• SOFF, G., RAFELSKI, J., & GREINER, W. (1973). LOWER BOUND TO LIMITING FIELDS IN NONLINEAR ELECTRODYNAMICS. PHYSICAL REVIEW A, 7(3), 903-907.
• Soff, G., Rafelski, J., & Greiner, W. (1973). Lower bound to limiting fields in nonlinear electrodynamics. Physical Review A, 7(3), 903-907.
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  Abstract: In view of new high-precision experiments in atomic physics it seems necessary to reexamine nonlinear theories of electrodynamics. The precise calculation of electronic and muonic atomic energies has been used to determine the possible size of the upper limit Emax to the electric field strength, which has been assumed to be a parameter. This is opposed to Born's idea of a purely electromagnetic origin of the electron's mass which determines Emax. We find Emax1.7×1020 V/cm. © 1973 The American Physical Society.
• DANOS, M., GREINER, W., & RAFELSKI, J. (1972). FIELDS NONLOCAL IN CLIFFORD SPACE .2. QUANTUM-THEORY OF INTERACTING FIELDS. ZEITSCHRIFT FUR PHYSIK, 258(2), 147-162.
• Danos, M., Greiner, W., & Rafelski, J. (1972). Fields nonlocal in Clifford space. I. Classical gauge-invariant nonlinear field theory. Physical Review D, 6(12), 3476-3491.
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  Abstract: A fully gauge-invariant, Lorentz-covariant, nonlocal, and nonlinear theory, for coupled spin-1/2 fields, ψ, and vector fields, A, i.e., "electrons" and "photons," is constructed. The field theory is linear in the ψ fields. The nonlinearity in the A fields arises unambiguously from the requirement of gauge invariance. The coordinates are generalized to admit hypercomplex values, i.e., they are taken to be Clifford numbers. The nonlocality is limited to the hypercomplex component of the coordinates. As the size of the nonlocality is reduced toward zero, the theory goes over into the inhomogeneous Dirac theory. The nonlocality parameter corresponds to an inverse mass and induces self-regulatory properties of the propagators. It is argued that in a gauge-invariant theory a graph-by-graph convergence is impossible in principle, but it is possible that convergence may hold for the complete solution, or for sums over classes of graphs. © 1972 The American Physical Society.
• KLEIN, A., & RAFELSKI, J. (1972). CONTRIBUTIONS TO PION-NUCLEUS OPTICAL-POTENTIAL NONLINEAR IN NUCLEAR DENSITY - ERICSON-ERICSON LORENTZ-LORENZ CORRECTION. PHYSICS LETTERS B, B 49(4), 318-322.
• Müller, B., Peitz, H., Rafelski, J., & Greiner, W. (1972). Solution of the dirac equation for strong external fields. Physical Review Letters, 28(19), 1235-1238.
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  Abstract: The 1s bound state of superheavy atoms and molecules reaches a binding energy of -2mc2 at 169. It is shown that the K shell is still localized in r space even beyond this critical proton number and that it has a width Γ (several keV large) which is a positron escape width for ionized K shells. The suggestion is made that this effect can be observed in the collision of very heavy ions (superheavy molecules) during the collision. © 1972 The American Physical Society.
• Müller, B., Rafelski, J., & Greiner, W. (1972). Auto-ionization of positrons in heavy ion collisions. Zeitschrift für Physik, 257(3), 183-211.
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  Abstract: Autoionization of positrons occurs as a fundamentally new process of quantum electrodynamics, if empty 1 s- or 2 p1/2- etc. electronic shells obtain binding energies larger than 2 mec2. This effect should be experimentally observable in the scattering of very heavy ions (Z≧80) on each other since in such collisions superheavy electronic molecules are formed (superheavy quasi-molecules). The scattering mechanism and the distribution of autoionization positrons are discussed. The adiabaticity of the heavy ion collision is studied and the electron-positron pair production background to the ionization problem is estimated. Analytic solutions are obtained for 1/r-potentials for the case Zα≧1. The phase shifts of negative energy solutions in the case of cutoff Coulomb potentials reveal the accuracy of the autoionization formalism. © 1972 Springer-Verlag.
• Müller, B., Rafelski, J., & Greiner, W. (1972). Electron shells in over-critical external fields. Zeitschrift für Physik, 257(1), 62-77.
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  Abstract: When the charge of a nucleus exceeds Z=Zcr≈ 164-172 the energy of the 1 s-electron level is lowered beyond the critical value of -mec2. Then this bound level is degenerated with negative energy continuum solutions of the Dirac equation and becomes a resonance, whose shape varies and is approximately of Breit-Wigner type for Z-Zcr≳5. The physical meaning of this resonance can be understood most easily if the 1 s-level is unoccupied (K-hole). In this case a positron may escape if Z>Zcr, a process, that can be interpreted as auto-ionization of the positron. This fundamentally new process of quantum electrodynamics of strong fields can be tested experimentally by scattering very heavy ions (Z≧80) on each other since in such collisions superheavy electronic molecules occur (superheavy quasimolecules). © 1972 Springer-Verlag.
• RAFELSKI, J., & KLEIN, A. (1972). POSSIBLE MEASUREMENT OF VACUUM POLARIZATION IN HEAVY-ION SCATTERING. PHYSICAL REVIEW C, 9(5), 1756-1759.
• RAFELSKI, J., GREINER, W., & FULCHER, L. (1972). SUPERHEAVY ELEMENTS AND NONLINEAR ELECTRODYNAMICS. NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA B-GENERAL PHYSICS RELATIVITY ASTRONOMY AND MATHEMATICAL PHYSICS AND METHODS, B 13(1), 135-160.
• RAFELSKI, J., MULLER, B., & GREINER, W. (1972). CHARGED VACUUM IN OVER-CRITICAL FIELDS. NUCLEAR PHYSICS B, B 68(2), 585-604.
• RAFELSKI, J., MULLER, B., SOFF, G., & GREINER, W. (1972). CRITICAL DISCUSSION OF VACUUM POLARIZATION MEASUREMENTS IN MUONIC ATOMS. ANNALS OF PHYSICS, 88(2), 419-453.
• Rafelski, J., Fulcher, L. P., & Greiner, W. (1972). A condition for vanishing electromagnetic self-stress in nonlinear classical electrodynamics. Il Nuovo Cimento, 7(1), 137-144.
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  Abstract: A condition for a vanishing electromagnetic self-stress is established, which also leads to a finite electromagnetic self-energy. Maxwell's theory does not satisfy this requirement. A class of nonlinear theories, which includes that of Born and Infeld, satisfies the condition. © 1972 Società Italiana di Fisica.
• Rafelski, J., Müller, B., & Greiner, W. (1972). Superheavy electronic molecules. Lettere Al Nuovo Cimento Series 2, 4(11), 469-474.
• SOFF, G., MULLER, B., & RAFELSKI, J. (1972). PRECISE VALUES FOR CRITICAL FIELDS IN QUANTUM ELECTRODYNAMICS. ZEITSCHRIFT FUR NATURFORSCHUNG SECTION A-A JOURNAL OF PHYSICAL SCIENCES, A 29(9), 1267-1275.
• Rafelski, J., Fulcher, L. P., & Greiner, W. (1971). Superheavy elements and an upper limit to the electric field strength. Physical Review Letters, 27(14), 958-961.
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  Abstract: An upper limit to the electric field strength, such as that of the nonlinear electrodynamics of Born and Infeld, leads to dramatic differences in the energy eigenvalues and wave functions of atomic electrons bound to superheavy nuclei. For example, the 1s12 energy level joins the lower continuum at Z=215 instead of Z=174, the value obtained when Maxwell's equations are used to determine the electric field. © 1971 The American Physical Society.
• SOFF, G., MULLER, B., RAFELSKI, J., & GREINER, W. (1971). SOLUTION OF DIRAC EQUATION FOR SCALAR POTENTIALS AND ITS IMPLICATIONS IN ATOMIC PHYSICS. ZEITSCHRIFT FUR NATURFORSCHUNG SECTION A-A JOURNAL OF PHYSICAL SCIENCES, A 28(9), 1389-1396.

Proceedings Publications

• Yang, C. T., & Rafelski, J. (2022, 2022-02-01). Reactions Governing Strangeness Abundance in Primordial Universe. In EPJ Web Conf., 259, 13001.
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  Strangeness production processes can balance natural strangeness decay in the early hadronic Universe. Comparing to the characteristic Hubble time 1/H, the reaction rates for μ± + νμ → K±, l− + l+ → ϕ, and π+π → K in sequence become slower than expansion rate at T = 33.9 MeV, T = 25MeV and T = 20MeV respectively. This means that in the antibaryon annihilation epoch near to T ≃ 40MeV strangeness is in chemical equilibrium.
• Rafelski, J. (2016, 2016-11-04). Hagedorn legacy. In 4th International Conference on New Frontiers in Physics, 126, 03001.
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  These remarks open the one-day session "50 years of Hagedorn's Temperatureand the Statistical Bootstrap Model". These developments set the path at CERNtowards the discovery of Quark-Gluon Plasma in the year 2000.[Journal_ref: ]
• Rafelski, J., & Birrell, J. (2016, August/2016). The hot Hagedorn Universe. In The hot Hagedorn Universe ICFNP2015, 126, 03005.
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  In the context of the half-centenary of Hagedorn temperature and the statistical bootstrap model (SBM) we present a short account of how these insights coincided with the establishment of the hot big-bang model (BBM) and helped resolve some of the early philosophical difficulties. We then turn attention to the present day context and show the dominance of strong interaction quark and gluon degrees of freedom in the early stage, helping to characterize the properties of the hot Universe. We focus attention on the current experimental insights about cosmic microwave background (CMB) temperature fluctuation, and develop a much improved understanding of the neutrino freeze-out, in this way paving the path to the opening of a direct connection of quark-gluon plasma (QGP) physics in the early Universe with the QCD-lattice, and the study of the properties of QGP formed in the laboratory.
• Labun, L., Rafelski, J., & Chen, P. (2013, 2013). TEMPERATURE OF ELECTRON FLUCTUATIONS IN AN ACCELERATED VACUUM. In TOWARDS ULTIMATE UNDERSTANDING OF THE UNIVERSE, 153-158.
• Petran, M., Letessier, J., Petracek, V., & Rafelski, J. (2014, Fall). Charm decay as a source of multistrange hadrons. In Strangeness In Quark Matter 2013 Birmingham, 509.
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  We describe a newly formulated approach to account for charm production and decay in Statistical Hadronization approach. Considering Pb-Pb collisions at = 2.76 TeV at LHC we show that charm hadron decays can be a significant contributor to the multistrange hadron abundance. We discuss the magnitude of expected effects as a function of charm yield.
• Petran, M., Letessier, J., Petracek, V., & Rafelski, J. (2014, Fall). Interpretation of strange hadron production at LHC. In Strangeness In Quark Matter 2013 Birmingham, 509.
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  We extend the SHM analysis of hadron production results showing here consistency with the increased experimental data set, stability of the fit with regard to inclusion of finite resonance widths and 2-star hyperon resonances. We present new results on strangeness yield as a function of centrality and present their interpretation in terms of QGP inspired model of strangeness abundance in the hadronizing fireball.
• Rafelski, J., & Birrell, J. (2014, Spring). Traveling Through the Universe: Back in Time to the Quark-Gluon Plasma Era. In Strangeness In Quark Matter 2013 Birmingham, 509.
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  We survey the early history of the discovery of quark gluon plasma and the early history of the Universe, beginning with the present day and reaching deep into QGP and almost beyond. We introduce cosmological Universe dynamics and connect the different Universe epochs with one another. We describe some of the many remaining open questions that emerge.
• Rafelski, J., & Petran, M. (2014, Spring). Universal QGP Hadronization Conditions at RHIC and LHC. In Wiegner 111 Budapest, 78.
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  We address the principles governing QGP hadronization and particle production in relativistic heavy-ion collisions. We argue that chemical non-equilibrium is required and show that once this condition is assumed a very good description of hadron production in collider RHIC and at LHC heavy ion experiments follows. We present results of our analysis as a function of centrality. Comparing most extreme experimental conditions we show that only the reaction volume and degree of strangeness phase space saturation change. We determine the universal QGP fireball hadronization conditions.
• Labun, L., & Rafelski, J. (2013, April). How top quark dipole moments affect Higgs decay. In 2013 APS April Meeting, 58.
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  Other Information: 11008
• Labun, L., & Rafelski, J. (2013, Fall). Temperature of Electron Fluctuations in an Accelerated Vacuum. In NOT PROVIDED, 28.
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  Other Information: 1340015
• Rafelski, J., & Labun, L. (2013, April). QED vacuum fluctuations as a function of magnetic moment. In 2013 APS April Meeting, 58.
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  Other Information: 15008
• Rafelski, J., & Labun, L. (2013, Fall). Critical Acceleration and Quantum Vacuum. In NOT PROVIDED, 28.
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  Other Information: 1340014
• Rafelski, J., & Labun, L. (2013, Fall). Strong fields and QED as function of the g-factor. In 2012 Fall Meeting of the APS Division of Nuclear Physics, 57.
• Rafelski, J., & Rafelsk, J. (2013, Fall). In the beginning\ ldots. In 2013 Fall Meeting of the APS Division of Nuclear Physics, 58.
• Rafelski, J., Labun, L., Hadad, Y., & Dumitras, D. (2013, 2010). Horizons of Strong Field Physics. In LIGHT AT EXTREME INTENSITIES: OPPORTUNITIES AND TECHNOLOGICAL ISSUES OF THE EXTREME LIGHT INFRASTRUCTURE, 1228, 39-53.
• Rafelski, J., Petran, M., & Rafelsk, J. (2013, Fall). Decay of charmed hadrons--SHARE with CHARM. In 2013 Fall Meeting of the APS Division of Nuclear Physics, 58.
• Rafelski, J., Petran, M., & Rafelsk, J. (2013, Fall). Universality of Hadronization Condition at RHIC and LHC. In 2013 Fall Meeting of the APS Division of Nuclear Physics, 58.
• Birrell, J., Labun, L., & Rafelski, J. (2012, April). Impacts by Compact Ultra Dense Objects. In 2012 APS April Meeting, 57.
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  Other Information: 7008
• Labun, L., & Rafelski, J. (2012, April). Signature of Spontaneous Particle Production in Converging Laser Pulses. In 2012 APS April Meeting, 57.
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  Other Information: 14002
• Labun, L., & Rafelski, J. (2012, April). Temperature of the Vacuum Accelerated by External Fields. In 2012 APS April Meeting, 57.
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  Other Information: 1020
• Labun, L., & Rafelski, J. (2012, Fall). Nonlinear Electromagnetic Forces in Astrophysics. In NOT PROVIDED, 43.
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  Other Information: 2237
• Labun, L., & Rafelski, J. (2012, Fall). Planetary Impacts by Clustered Quark Matter Strangelets. In NOT PROVIDED, 5.
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  Other Information: 381
• Miller, G., Thomas, A., Carroll, J., & Rafelski, J. (2012, Fall). Resolution of the proton radius puzzle via off-shell form factors. In 19TH PARTICLES AND NUCLEI INTERNATIONAL CONFERENCE (PANIC11).
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  Other Information: 1441, 150
• Miller, G., Thomas, A., Carroll, J., & Rafelski, J. (2012, May). What's new with the neutron and proton. In NOT PROVIDED, 52, 1357-1366.
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  In: LIGHTCONE 2011: Applications of Light-Cone Coordinates to Highly Relativistic Systems
• Petran, M., Letessier, J., Petracek, V., & Rafelski, J. (2012, Fall). Strangeness Production in Au-Au collisions at \sqrt{s_{NN =62.4 GeV. In NOT PROVIDED, 5.
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  Other Information: 255
• Rafelski, J. (2012, Fall). Strangeness and Quark--Gluon Plasma. In NOT PROVIDED, 43.
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  Other Information: 829
• Rafelski, J., & Rafelsk, J. (2012, April). Strangeness Signature of Quark Gluon Plasma at LHC. In 2012 APS April Meeting, 57.
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  Other Information: 10001
• Rafelski, J., Dietl, C., & Labun, L. (2012, Fall). Compact Ultradense Objects in the Solar System. In NOT PROVIDED, 43.
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  Other Information: 2251
• Rafelski, J., Birrell, J., Evans, D., Hands, S., Lietava, R., Romita, R., & Baillie, O. (2010, 2014). Traveling Through the Universe: Back in Time to the Quark-Gluon Plasma Era. In 14TH INTERNATIONAL CONFERENCE ON STRANGENESS IN QUARK MATTER (SQM2013), 509.
• Rafelski, J., Labun, L., & Chen, P. (2008, 2013). CRITICAL ACCELERATION AND QUANTUM VACUUM. In TOWARDS ULTIMATE UNDERSTANDING OF THE UNIVERSE, 141-152.
• Torrieri, G., Jeon, S., Rafelski, J., Simak, ., Sumbera, M., Todorova, S., & Tomasik, B. (2008, 2006). Particle multiplicities and fluctuations in 200 GeVAu-Au collisions. In MULTIPARTICLE DYNAMICS, 828, 55-61.
• Carroll, J. D., Thomas, A. W., Rafelski, J., Miller, G. A., Kizilersu, A., & Thomas, A. (2007, 2011). The Radius of the Proton: Size Does Matter. In T(R)OPICAL QCD 2010, 1354.
• Miller, G. A., Thomas, A. W., Carroll, J. D., Rafelski, J., Steadman, S., Stephans, G., & Taylor, F. (2006, 2012). Resolution of the Proton Radius Puzzle via Off-shell Form Factors. In 19TH PARTICLES AND NUCLEI INTERNATIONAL CONFERENCE (PANIC11), 1441, 150-152.
• Rafelski, J., & Letessier, J. (2006, 2006-11-01). Strangeness and thresholds of phase changes in relativistic heavy ion collisions. In Cairns Topical Workshop on Light-Cone QCD and Nonperturbative Hadron Physics, 161, 200-209.
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  Abstract: We discuss how the dynamics of the evolving hot fireball of quark-gluon matter impacts phase transition between the deconfined and confined state of matter. The rapid expansion of the fireball of deconfined matter created in heavy ion collisions facilitates formation of an over-saturated strange quark phase space. The related excess abundance of strangeness is compensating the suppression of this semi-heavy quark yield by its quark mass. In addition, the dynamical expansion of colored quanta pushes against the vacuum structure, with a resulting supercooling of the transition temperature. We address the status of the search for the phase boundary as function of reaction energy and collision centrality and show evidence for a change in reaction mechanism at sufficiently low energies. The phase diagram derived from the study of hadron production conditions shows two boundaries, one corresponding to the expected transition between confined and deconfined matter, with a downward temperature shift, and the other a high quark density hadronization which appears to involve heavy effective quarks, at relatively large temperatures. © 2006 Elsevier B.V. All rights reserved.
• , ., & , . (2002). New states of matter in hadronic interactions. Proceedings, Pan-American Advanced Study Institute, PASI 2002, Campos do Jordao, Sao Paulo, Brazil, January 7-18, 2002.
• Elze, H. T., Rafelski, J., & Turko, L. (2002). Entropy Production in Relativistic Hydrodynamics. In Non-Perturbative QCD.
• Rafelski, J., & Letessier, J. (2002). Hadronic signature of quark-gluon plasma. In Quark confinement and the hadron spectrum. Proceedings, 5th International Conference, Gargnano, Italy, September 10-14, 2002.
• Rafelski, J., & Letessier, J. (2002). Probing dense matter with strange hadrons. In Non-Perturbative QCD.
• Rafelski, J., Torrieri, G., & Letessier, J. (2002). Strangeness and QGP freezeout dynamics. In Proceedings, 36th Rencontres de Moriond on QCD and High Energy Hadronic Interactions: Les Arcs, France, Mar 17-24, 2001.

Presentations

• Rafelski, J. (2020, January). Special Relativity and Strong Fields. Colloquium Lecture. Institute of Physics, University of Dusseldorf.
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  Special Relativity and Strong Fields
• Rafelski, J. (2019, January). Strangness and Formation of QGP. Epiphany 2019 Conference. Krakow Poland.
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  Strangness and Formation of QGP
• Rafelski, J. (2019, June). Compact Utradense Objects: Something Strange is Flying Around. Balaton-workshop. Lake Balaton Hungary.
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  Compact Utradense Objects: Something Strange is Flying Around
• Rafelski, J. (2018, June). Quantum Vacuum and Strong Fields. Colloquium at Wigner Institute. Budapest: Hungarian Academy of Science.
• Rafelski, J. (2018, March). The Acceleration Frontier in Particle Physics. ELI-Beamlines Laboratory Colloquium. Prague.
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  The Acceleration Frontier in Particle Physics
• Rafelski, J. (2017, December 15). Something Strange is Flying Around. Physics Colloquium. Wroclaw, Poland: University Wroclaw.
• Rafelski, J. (2017, December). Relativity Matters: The Acceleration Frontier. Physics Colloquium EPFL (Ecole Polytechnique Federale Lausanne). Lausanne, SWITZERLAND.
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  Relativity Matters: The Acceleration Frontier
• Rafelski, J. (2017, July 24). Relativity Matters: The Acceleration Frontier. Department of Physics Colloquium. Bogota, Colombia: Uni Andes.
• Rafelski, J. (2017, July 25). All About the Quantum Vacuum. Third Andean School on Nuclear Physics: QCD, QGP, HI Collisions. Bogota, Colombia: Uni Andes.
• Rafelski, J. (2017, July). Three Lectures on Strangness Signatures of Quark-Gluon Plasma. Third Andean School on Nuclear Physics: QCD, QGP, HI Collisions at Uni Andes. Bogota, Colombia.
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  Three Lectures on Strangness Signatures of Quark-Gluon Plasma Third Andean School on Nuclear Physics: QCD, QGP, HI Collisions at Uni Andes
• Rafelski, J. (2017, June). Die Erste Stunde. FIAS International Symposium on Discoveries at the Frontiers of Science. Frankfurt, GERMANY.
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  The first hour: how a new field of physics was created in Frankfurt beginning in 1968: Strong field physics. Presentation In honor of W. Greiner
• Rafelski, J. (2017, September). Evolution of Matter in the Universe from quark-gluon plasma era to the present. Physics Colloquium NY City College Graduate Center. New York, NY.
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  Evolution of Matter in the Universe from quark-gluon plasma era to the present
• Rafelski, J. (2017, September). Strangeness from quark-gluon plasma. Physics Colloquium. Norfolk: Old Dominion University.
• Rafelski, J. (2016, Fall). Critical Fields=Critical Acceleration = Particle Production. Colloquium. University Frankfurt: Fachbereich Physik.
• Rafelski, J. (2016, Fall). Decelerating Partons: Accelerating Science with SM. XII Polish Workshop on RHIC - From Instabilities to Fluctuations. Kielce, Poland: Jan Kochanowski University.
• Rafelski, J. (2016, Fall). Exploring the QCD Phase Diagram with Strangenes. Exploring the QCD Phase Diagram through Energy Scans INT-16-3. Seattle, Institute Nuclear Theory: INT-Seattle.
• Rafelski, J. (2016, Fall). QGP in the Universe and in the Laboratory. Departmental Colloquium. Washington DC: George Washington University,.
• Rafelski, J. (2016, Spring). ELI-BL/Institute of Physics Prague Colloquium March 2016. ELI-BL Symposium, PragueEuropean Light Infrastructure.
• Rafelski, J. (2016, Summer). Charting the future frontier(s) of particle production. Particle Production in Hadronic Collisions. Krakow: Jagiellonian University.
• Rafelski, J. (2016, Summer). QGP in the Universe and in the Laboratory. Research Seminar University of Washington.
• Rafelski, J. (2016, Summer). Something STRANGE is flying around. Departmental Colloquiumm.
• Rafelski, J. (2016, Summer). The Mar(e)k of QGP: Strangeness and Entropy. CPOD 2016. Wroclaw: University.
• Rafelski, J. (2015, April). New Insights into the Time Evolution of the Universe. Clark Fest 2015. St Louis: Department of Physics, Washington University.
• Rafelski, J. (2015, August). Hagedorn Session Conference Opening. ICFNP2015 // Hagedorn Session. Crete, Greece: CERN and ICFNP2015.
• Rafelski, J. (2015, August). Time Evolution of the Hot Hagedorn Universe. ICFNP 2015. Crete, Greece: CERN and ICFNP2015.
• Rafelski, J. (2015, December). QGP in the Universe and in the Laboratory. Institutes Colloquium. Vienna, Austria: Stefan Meier Institute.
• Rafelski, J. (2015, January). Quark-Gluon Plasma as the Possible Source of Cosmological Dark Radiation. UCLA Chiral Symmetry Workshop. Los Angeles: Department of Physics, University of California at Los Angeles.
• Rafelski, J. (2015, June). Boiling Quarks, Melting Hadrons. Wigner Colloquium. Budapest: Wigner Research Institute.
• Rafelski, J. (2015, May 2015). Quark-Gluon Plasma as the Possible Source of Cosmological Dark Radiation. CERN Experiment NA61 Collaboration Meeting Paris. Paris, France: CERN and Unversity Paris Jussieu.
• Rafelski, J. (2015, November). Physics of Strong Fields: Foundations and Applications. Greinerium 2015. Makutsi: Frankfurt institute for Advanced Studies, Germany.
• Rafelski, J. (2015, November). QGP in the Universe Particles in the Universe. Greinerium Makutsi 2015. Makutsi: Frankfurt institute for Advanced Studies, Germany.
• Rafelski, J. (2015, November). ‘Hagedorn Legacy’ 50 y of Hagedorn Temperature Introductory Remarks,. CERN symposium. CERN, Geneva: CERN.
• Rafelski, J. (2015, October). Near Beginning of Time . . . There Was QGP. University of California, Irvine Particle Physics Colloquium. Irvine: UC Irvine.
• Rafelski, J. (2015, September). Near Beginning of Time . . . There Was QGP. Departmental Colloqium. Lawrence, Kansas: University of Kansas.
• Rafelski, J. (2014, April). (K)CUDOs at PSI-Tucson. Tucson Planetary Science Institute Seminar.
• Rafelski, J. (2014, April). Traveling through the Universe: Back in Time to the Quark-Gluon Plasma Era. Notre Dame University Department of Physics Colloquium.
• Rafelski, J. (2014, February). QCD Phases studied by means of hadron production. HECOLS Workshop and XXXII Max-Born Symposium. Wroclaw, Poland: University Wroclaw.
• Rafelski, J. (2014, January). Critical acceleration = Critical force = Critical field. Physics Department Colloquium. Prague, Chech Rep.
• Rafelski, J. (2014, January). QGP: Journey in the Universe. Brookhaven National Laboratory Physics Department Colloquium. Upton New York: Department of Energy.
• Rafelski, J. (2014, March). Reconsideration of Statistical Hadronization in Light of LHC Results. CERN Heavy Ion Forum. Heavy Ion Forum: CERN.
• Rafelski, J., & Petran, M. (2014, April). Reconsideration of Statistical Hadronization in Light of LHC Results. 2014 APS April Meeting. Savannah, Giorgia: Bulletin of the American Physical Society.

Poster Presentations

• Rafelski, J. (2013, April). A new scheme for pB fusion. Technical University Physics Colloquium. Prague, Check Rep.
• Rafelski, J. (2013, April). Critical acceleration: probing elementary interactions in laser-electron scattering. SPIE "Research Using Extreme Light: Entering New Frontiers with Petawatt-Class Lasers meeting'' Conference. Prague.
• Rafelski, J. (2013, December). A new scheme for pB fusion. Physics Department Colloquium. Bergen, Norway.
• Rafelski, J. (2013, December). Universality of Hadronization Condition. Yukawa Symposium. Osaka, Japan.
• Rafelski, J. (2013, July). (K)CUDOs in Berlin. Physics and Geology Colloquium. Berlin, Germany.
• Rafelski, J. (2013, July). Connecting QGP-RHI physics to the Early Universe. SQM2013 International Meeting. Birmingham, UK.
• Rafelski, J. (2013, July). Universality of Hadronization Condition at RHIC and LHC. FIAS Seminar. Frankfurt, Germany.
• Rafelski, J. (2013, June). (K)CUDOs for Iwo. Polish Academy Symposium 80Y Iwo Bialynicki Birula. Warsaw, Poland.
• Rafelski, J. (2013, June). Quantum Vacuum, the primordial imponderable "matter”. ELI-Beamlines Physics Seminar. Prague, Check Rep.
• Rafelski, J. (2013, June). Universal Hadronization Conditions at RHIC and LHC. Max Born Symposium "Critical Behavior in Hot and Dense QCD”. Wroclaw, Poland.
• Rafelski, J. (2013, June). Universal QGP hadronization condition. STAR-RHIC regional collaboration meeting. Prague, Chech Rep.
• Rafelski, J. (2013, March). Compact Ultra Dense Object (CUDO) Impacts. UTEP Physics Colloquium.
• Rafelski, J. (2013, March). Compact Ultra Dense Objects (CUDOs). Washington University St Louis Physics Seminar.
• Rafelski, J. (2013, March). Laser-electron scattering at the critical force limit. Northern Illinois University Physics Colloquium.
• Rafelski, J. (2013, May). A new scheme for pB fusion. Duke University Seminar. Durham.
• Rafelski, J. (2013, November). QGP: Universal Hadronization. Wigner 101 Symposium. Budapest.
• Rafelski, J. (2013, October). In the beginning... there was Quark-Gluon Plasma. APS-DNP Meeting. Newport Beach.
• Petran, M., Letessier, J., & Rafelski, J. (2012, August). Charm contribution to final hadron yield at LHC SHARE with CHARM describes PbPb hadron yields at 2.76 TeV Bulk properties of hot QCD matter at RHIC and LHC and Universal QGP hadronization condition. QUARK MATTER 2013. Washington DC.
• Rafelski, J. (2012, April). Hadronization of Quark Gluon Plasma at LHC. APS April meeting. Anaheim, CA.
• Rafelski, J. (2012, February). Critical Acceleration. Leung Center of Astrophysics. Taipei, Taiwan: National University.
• Rafelski, J. (2012, January). Critical Acceleration and Vacuum Structure. Munich LMU Sommerfeld Center Colloquium.
• Rafelski, J. (2012, June). (K)CUDOS for Joe. Kapusta Fest. Montreal.
• Rafelski, J. (2012, March). Discovery of Quark-GLuon Plasma. ICRA Center SeminarUniversity Rome.
• Rafelski, J. (2012, March). Quark-Gluon Plasma in the Early Universe. ICRA Center SeminarUniversity Rome.
• Rafelski, J. (2012, March). Renaissance of Strong Field Physics: Critical Acceleration and Laser Pulses. ICRA lectureUniversity Rome.
• Rafelski, J. (2012, May). From Quark-Gluon Plasma to Neutrino Decoupling. Invited Lecture at the Krakow School of Theoretical Physics. Zakopane.
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  Other Information: 3 Lectures
• Rafelski, J. (2012, May). Solar System Signatures of Impacts by Compact Ultra Dense Objects. Symposium on occasion of 70th birthday of Remo RuffiniUniversity Rome La Sapienza.
• Rafelski, J. (2012, November). Hadron production in PbPb collisions at LHC. CERN Heavy Ion Forum.
• Rafelski, J. (2012, October). Strong fields and QED as function of the gyromagnetic factor. APS-DNP meeting. Newport Beach.

Reviews

• Rafelski, J. (2014. Einstein’s Physics: Atoms, Quanta, and Relativity – Derived, Explained, and Appraised(p. 47). March 2014.
• Rafelski, J. (2013. A Student’s Guide to Einstein’s Major Papers.
• Ruffini, R., & Rafelski, J. (2012. Obituary -- Fang Lizhi 1936–2012.

Case Studies

• Rafelski, J. (2016. Report on: Research in Theoretical High Energy Nuclear Physics at the University of Arizona(p. 24).
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  Principal Investigator: Johann Rafelski, Project and Reporting Period: June, 2004 - December, 2015In the past decade (2004-2015) we addressed the quest for the understanding of how quark confinement works, how it can be dissolved in a limited space-time domain, and what this means: i) for the paradigm of the laws of physics of present day; and, ii) for our understanding of cosmology.Addressing the quark-gluon phase (QGP) in laboratory we explore the physics governing the highly effective conversion of kinetic energy into abundant particle multiplicity. This is arguably the most remarkable feature of relativistic heavy ion (RHI) collisions. We devoted most of our effort to both phenomenological and theoretical understanding of this phenomenon which concerns the physics of ultra high acceleration. In our phenomenological analysis of experimental data we obtained the precise characterization of the QGP fireball at the time of hadronization. Our noteworthy results include the determination of universal conditions of fireball break-up into matter (hadronization), with universal pressure P = 80 ± 3 MeV/fm3. Hadronization conditions are obtained by computing the partial contributions of all hadron components in the final state, akin to the method used to compute flavor strangeness content of the fireball.Among pivotal questions about the early Universe we have addressed are: a) How QGP transits to the hot hadronic universe, that is hadronization mode, matter-antimatter annihilation; and more generally b) The evolution path connecting QGP to the BBN phase of the Universe; c) Application of the chemical nonequilibrium methods developed in the study of hadronization of QGP to characterize the properties of the free-streaming neutrinos in the early universe; d) Demonstration that hadrons in the Universe remain in chemical equilibrium at all temperatures is among noteworthy achievements; e) The study of the transition from hadronic to the leptonic Universe, and how this affects free-streaming neutrino spectrum which affects physics of the BBN era of the universe, and how the BBN observables could be affected.

Others

• Barish, K., Huang, H. Z., Kapusta, J., Odyniec, G., Rafelski, J., & Whitten, C. A. (2013, DEC). Special issue: SQM 2006 - International Conference on Strangeness in Quark Matter (University of California Los Angeles, 26-31 March 2006) - Preface. JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS.
• Birrell, J., & Rafelski, J. (2012, May). Possibility of Electroweak Phase Transition at Low Temperature. arXiv. http://arxiv.org/abs/1205.1011
• Rafelski, J., & Labun, L. (2012, May). A Cusp in QED at g=2. arXiv. http://arxiv.org/abs/1205.1835
• Labun, L., & Rafelski, J. (2010, October). Higgs two-gluon decay and the top-quark chromomagnetic moment. arXiv. http://arxiv.org/abs/1210.3150
• RAFELSKI, J. (2010, 1973). QUANTUM ELECTRODYNAMICS OF STRONG FIELDS IN HEAVY-ION COLLISIONS. BULLETIN OF THE AMERICAN PHYSICAL SOCIETY.
• FULCHER, L., RAFELSKI, J., & GREINER, W. (1974, 1972). SUPERHEAVY ELEMENTS AND QUANTUM ELECTRODYNAMICS. BULLETIN OF THE AMERICAN PHYSICAL SOCIETY.
• KLEIN, A., & RAFELSKI, J. (1974, 1974). STABILITY OF BOSE-VACUUM IN SUPERCRITICAL ELECTROMAGNETIC-FIELDS. BULLETIN OF THE AMERICAN PHYSICAL SOCIETY.