Strange Messages: Chemical and Thermal Freeze-out in Nuclear Collisions

Abstract

Thermal models are commonly used to interpret heavy-ion data on particle yields and spectra and to extract the conditions of chemical and thermal freeze-out in heavy-ion collisions. I discuss the usefulness and limitations of such thermal model analyses and review the experimental and theoretical evidence for thermalization in nuclear collisions. The crucial role of correlating strangeness production data with single particle spectra and two-particle correlation measurements is pointed out. A consistent dynamical picture for the heavy-ion data from the CERN SPS involves an initial prehadronic stage with deconfined color and with an appreciable isotropic pressure component. This requires an early onset of thermalization.

15 pages, 2 figures, talk given at Strange Quark Matter '98, Padova, Italy, 20-24 July 1998, to be published in J. Phys. G 25; final version with updated references

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Cited by in corpus (24)

• Chemical and Thermal Freeze-Out Parameters from 1 to 200 A.GeV
• Fluctuations of particle ratios and the abundance of hadronic resonances
• Primordial hadrosynthesis in the Little Bang
• Local equilibrium in heavy ion collisions. Microscopic model versus statistical model analysis
• The continuum limit of quark number susceptibilities
• The quark-gluon plasma at RHIC
• Using the Tsallis distribution for hadron spectra in $pp$ collisions: Pions and quarkonia at $\sqrt{s}$ = 5--13000 GeV
• Energy scan/dependence of kinetic freeze-out scenarios of multi-strange and other identified particles in central nucleus-nucleus collisions
• A hybrid model approach for strange and multi-strange hadrons in 2.76 A TeV Pb+Pb collisions
• Equation of state of resonance-rich matter in the central cell in heavy-ion collisions at $\sqrt{s}$=200 AGeV
• Local equilibrium in heavy-ion collisions: Microscopic analysis of a central cell versus infinite matter
• Particle Multiplicities and Thermalization in High Energy Collisions
• Systematics of chemical freeze-out parameters in heavy-ion collision experiments
• Information theory approach (extensive and nonextensive) to high energy multiple production processes
• Search for positively charged strangelets and other related results with E864 at the AGS
• Novel scheme for parametrizing the chemical freeze-out surface in Heavy Ion Collision Experiments
• Time Dependence of Chemical Freeze-out in Relativistic Heavy Ion Collisions
• Thermodynamic Signatures and Phase Transitions in High-Energy Au-Au Collisions
• Particle Ratios at CERN, BNL and GSI : Unified Description of Freeze-Out Parameters
• Particle abundances and spectra in the hydrodynamical description of relativistic nuclear collisions with light projectiles
• Is Strangeness still interesting at RHIC ?
• Color plasma oscillation in strangelets
• Conservation of particle multiplicities between chemical and thermal freeze-out
• Chemical freeze-out systematics of thermal model analysis using hadron yield ratios