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Title: Phase-space densities and effects of resonance decays in a hydrodynamic approach to heavy ion collisions

Abstract

A method allowing analysis of the overpopulation of phase space in heavy ion collisions in a model-independent way is proposed within the hydrodynamic approach. It makes it possible to extract a chemical potential of thermal pions at freeze-out, irrespective of the form of freeze-out (isothermal) hypersurface in Minkowski space and transverse flows on it. The contributions of resonance (with masses up to 2 GeV) decays to spectra, interferometry volumes, and phase-space densities are calculated and discussed in detail. The estimates of average phase-space densities and chemical potentials of thermal pions are obtained for SPS and RHIC energies. They demonstrate that multibosonic phenomena at those energies might be considered as a correction factor rather than as a significant physical effect. The analysis of the evolution of the pion average phase-space density in chemically frozen hadron systems shows that it is almost constant or slightly increases with time while the particle density and phase-space density at each space point decreases rapidly during the system's expansion. We found that, unlike the particle density, the average phase-space density has no direct link to the freeze-out criterion and final thermodynamic parameters, being connected rather to the initial phase-space density of hadronic matter formed in relativisticmore » nucleus-nucleus collisions.« less

Authors:
;  [1]
  1. Bogolyubov Institute for Theoretical Physics, Kiev 03143, Metrologichna 14b (Ukraine)
Publication Date:
OSTI Identifier:
20695832
Resource Type:
Journal Article
Journal Name:
Physical Review. C, Nuclear Physics
Additional Journal Information:
Journal Volume: 70; Journal Issue: 6; Other Information: DOI: 10.1103/PhysRevC.70.064901; (c) 2004 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0556-2813
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; BROOKHAVEN RHIC; CORRECTIONS; DENSITY; FREEZING OUT; HEAVY ION REACTIONS; HYDRODYNAMIC MODEL; INTERFEROMETRY; MINKOWSKI SPACE; PARTICLE DECAY; PHASE SPACE; PIONS; POTENTIALS; RELATIVISTIC RANGE

Citation Formats

Akkelin, S V, and Sinyukov, Yu M. Phase-space densities and effects of resonance decays in a hydrodynamic approach to heavy ion collisions. United States: N. p., 2004. Web. doi:10.1103/PhysRevC.70.064901.
Akkelin, S V, & Sinyukov, Yu M. Phase-space densities and effects of resonance decays in a hydrodynamic approach to heavy ion collisions. United States. doi:10.1103/PhysRevC.70.064901.
Akkelin, S V, and Sinyukov, Yu M. Wed . "Phase-space densities and effects of resonance decays in a hydrodynamic approach to heavy ion collisions". United States. doi:10.1103/PhysRevC.70.064901.
@article{osti_20695832,
title = {Phase-space densities and effects of resonance decays in a hydrodynamic approach to heavy ion collisions},
author = {Akkelin, S V and Sinyukov, Yu M},
abstractNote = {A method allowing analysis of the overpopulation of phase space in heavy ion collisions in a model-independent way is proposed within the hydrodynamic approach. It makes it possible to extract a chemical potential of thermal pions at freeze-out, irrespective of the form of freeze-out (isothermal) hypersurface in Minkowski space and transverse flows on it. The contributions of resonance (with masses up to 2 GeV) decays to spectra, interferometry volumes, and phase-space densities are calculated and discussed in detail. The estimates of average phase-space densities and chemical potentials of thermal pions are obtained for SPS and RHIC energies. They demonstrate that multibosonic phenomena at those energies might be considered as a correction factor rather than as a significant physical effect. The analysis of the evolution of the pion average phase-space density in chemically frozen hadron systems shows that it is almost constant or slightly increases with time while the particle density and phase-space density at each space point decreases rapidly during the system's expansion. We found that, unlike the particle density, the average phase-space density has no direct link to the freeze-out criterion and final thermodynamic parameters, being connected rather to the initial phase-space density of hadronic matter formed in relativistic nucleus-nucleus collisions.},
doi = {10.1103/PhysRevC.70.064901},
journal = {Physical Review. C, Nuclear Physics},
issn = {0556-2813},
number = 6,
volume = 70,
place = {United States},
year = {2004},
month = {12}
}