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Jan Rafelski

Publications and source records attributed to Jan Rafelski.

At least 19 recordsLinked to original sources
arXiv2022

QCD phase transition studied by means of hadron production

This is a brief review of our work describing the hadronization process of a QGP fireball formed in relativistic heavy-ion collisions. We introduce the SHARE method of analysis of hadron multiplicities. Using this tool we describe in consistent continuos manner the yield of all hadrons produced in the available range of reaction energies and centralities. 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 that the final state is differentiated solely by: i) volume changes; and ii) flavor (strangeness, charm) content. Conversely, emerging particles add up to create universal hadronization pressure $P = 80 \pm 3$ MeV/fm$^3$ for all considered collision systems. The relative strangeness to entropy content of a large fireball is found to be that of quark-gluon plasma degrees of freedom near the chemical QGP equilibrium. This 'Universal Hadronization' condition common to SPS, RHIC, and LHC agrees with the proposed reaction picture of a direct QGP fireball evaporation into free-streaming hadrons.

hep-ph↗
arXiv2021

The muon abundance in the primordial Universe

Muon abundance is required for the understanding of several fundamental questions regarding properties of the primordial Universe. In this paper we evaluate the production and decay rates of muons in the cosmic plasma as a function of temperature. This allows us to determine when exactly the muon abundance disappears. When the Universe cools below the temperature $kT_\mathrm{disappear}\approx 4.135$ MeV the muon decay rate overwhelms production rates and muons vanish quasi-instantaneously from the Universe. Interestingly, we show that at $T_\mathrm{disappear}$ the muon number is nearly equal to baryon abundance.

hep-ph↗
arXiv2017

The Mar(e)k of QGP: Strangeness

Strangeness signature of 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.

hep-ph↗
arXiv2016

Charting the future frontier(s) of particle production

This short note describes the long collaborative effort between Arizona and Kraków, showing some of the key strangeness signatures of quark-gluon plasma. It further presents an annotated catalog of foundational questions defining the research frontiers which I believe can be addressed in the foreseeable future in the context of relativistic heavy ion collision experiments. The list includes topics that are specific to the field, and ventures towards the known-to-be-unknown that may have a better chance with ions as compared to elementary interactions.

hep-ph↗
arXiv2014

Strangeness in QGP: Hadronization Pressure

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\pm 3\,\mathrm{MeV/fm}^3 $.

nucl-th↗
arXiv2013

Nonlinear Electromagnetic Forces in Astrophysics

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.

astro-ph.HE↗
arXiv2012

From Quark-Gluon Universe to Neutrino Decoupling: 200<T<2MeV

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 is described in detail.

nucl-th↗
arXiv2011

Strangeness and Quark--Gluon Plasma

I review the foundational motivation 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 quark-gluon plasma (QGP) phase filling the Universe for the first 30$μ$s after the big-bang; the origin of stable matter mass; and of the origin of flavor. The special role of strangeness enhancement and strange antibaryon signature is 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.

nucl-th↗
arXiv2011

Strangeness Production in Au--Au collisions at $\sqrt{s_{NN}}=62.4$ GeV

We obtain strangeness production as function of centrality in a statistical hadronization model analysis of all experimental hadron production data in Au--Au collisions at $\sqrt{s_{NN}}=62.4\GeV$. Our analysis describes successfully the yield of strange and multi-strange hadrons recently published. We explore condition of hadronization as a function of centrality and find universality for the case of chemical non-equilibrium in the hadron phase space corresponding to quark--gluon plasma (QGP) in chemical equilibrium.

hep-ph↗
arXiv2010

Statistical Hadronization of Multistrange Particles

We study multistrange hadrons produced in NA49 and STAR experiments at center of mass energies varying from \sqrt{s_{NN}} = 7.61 GeV to 200 GeV. We show that the yields of Ξ, Ξ-bar 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.

hep-ph↗
arXiv2010

Strong Field Physics: Probing Critical Acceleration and Inertia with Laser Pulses and Quark-Gluon Plasma

Understanding physics in domains of critical (quantum unstable) fields requires investigating the classical and quantum particle dynamics at the critical acceleration, $\dot u \to 1$ [natural units]. This regime of physics remains today experimentally practically untested. Particle and light collision experiments reaching critical acceleration are becoming feasible, in particular applying available high intensity laser technology. 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.

hep-ph↗
arXiv2006

Status of Strangeness-Flavor Signature of QGP

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 measurement help understand the dense hadronic matter.

hep-ph↗
arXiv2003

Strangeness and Statistical Hadronization: How to Study Quark-Gluon Plasma

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 multiplicities 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.

hep-ph↗
arXiv2000

Macroconstraints from Microsymmetries of Macrosystems

The dynamics governing the evolution of a many body system is constrained by a nonabelian local symmetry. We obtain a general form of the global macroscopic conditions assuring that at the microscopic level the evolution respects the overall symmetry constraint. These conditions does not depend on detailed dynamics of the system. It is shown that a nonabelian internal symmetry leads to the new subsidiary condition imposed on the system. A structure of constraints is analysed.

nucl-th↗
arXiv2000

Dynamics of Multiparticle Systems with non - Abelian Symmetry

We consider the dynamics governing the evolution of a many body system constrained by an 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').

hep-th↗
arXiv1999

Diagnosis of QGP with Strange Hadrons

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--200AGeV 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.

hep-ph↗
arXiv1997

Formation and Evolution of the Quark-Gluon Plasma

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.

hep-ph↗