Local equilibrium in heavy ion collisions. Microscopic model versus statistical model analysis

  • The assumption of local equilibrium in relativistic heavy ion collisions at energies from 10.7 AGeV (AGS) up to 160 AGeV (SPS) is checked in the microscopic transport model. Dynamical calculations performed for a central cell in the reaction are compared to the predictions of the thermal statistical model. We find that kinetic, thermal and chemical equilibration of the expanding hadronic matter are nearly approached late in central collisions at AGS energy for t >= 10 fm/c in a central cell. At these times the equation of state may be approximated by a simple dependence P ~= (0.12-0.15) epsilon. Increasing deviations of the yields and the energy spectra of hadrons from statistical model values are observed for increasing energy, 40 AGeV and 160 AGeV. These violations of local equilibrium indicate that a fully equilibrated state is not reached, not even in the central cell of heavy ion collisions at energies above 10 AGeV. The origin of these findings is traced to the multiparticle decays of strings and many-body decays of resonances.

Download full text files

Export metadata

Additional Services

Share in Twitter Search Google Scholar
Metadaten
Author:Larissa BravinaORCiDGND, Eugene E. ZabrodinORCiD, Mark I. GorensteinORCiDGND, Steffen A. BassORCiDGND, Mohamed Belkacem, Marcus BleicherORCiDGND, Mathias Brandstetter, Christoph Ernst, Markus Hofmann, Ludwig NeiseGND, Sven SoffORCiD, Henning WeberGND, Horst StöckerORCiDGND, Walter GreinerGND
URN:urn:nbn:de:hebis:30-7074
URL:http://de.arxiv.org/abs/hep-ph/9906548
Document Type:Preprint
Language:English
Date of Publication (online):2005/04/14
Year of first Publication:1999
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2005/04/14
Note:
REVTEX, 37 pages (incl. 20 figs.), to be published in Phys.Rev. C60 (1999) 024904
Source:http://de.arxiv.org/abs/hep-ph/9906548 , REVTEX, 37 pages (incl. 20 figs.), to be published in Phys.Rev. C60 (1999) 024904
HeBIS-PPN:128789549
Institutes:Physik / Physik
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik
PACS-Classification:20.00.00 NUCLEAR PHYSICS / 24.00.00 Nuclear reactions: general / 24.10.-i Nuclear reaction models and methods / 24.10.Lx Monte Carlo simulations (including hadron and parton cascades and string breaking models)
20.00.00 NUCLEAR PHYSICS / 24.00.00 Nuclear reactions: general / 24.10.-i Nuclear reaction models and methods / 24.10.Pa Thermal and statistical models
20.00.00 NUCLEAR PHYSICS / 25.00.00 Nuclear reactions: specific reactions / 25.75.-q Relativistic heavy-ion collisions (collisions induced by light ions studied to calibrate relativistic heavy-ion collisions should be classified under both 25.75.-q and sections 13 or 25 appropriate to the light ions)
Licence (German):License LogoDeutsches Urheberrecht