TY  - JOUR
A1  - Bravina, Larissa
A1  - Gorenstein, Mark I.
A1  - Zabrodin, Eugene E.
A1  - Bass, Steffen A.
A1  - Belkacem, Mohamed
A1  - Bleicher, Marcus
A1  - Brandstetter, Mathias
A1  - Hofmann, Markus
A1  - Soff, Sven
A1  - Spieles, Christian
A1  - Weber, H.
A1  - Stöcker, Horst
A1  - Greiner, Walter
T1  - Equilibrium and nonequilibrium effects in nucleus nucleus collisions
T2  - Physics letter B
N2  - Abstract: Local thermal and chemical equilibration is studied for central AqA collisions at 10.7 160 AGeV in the Ultrarelativis- . tic Quantum Molecular Dynamics model UrQMD . The UrQMD model exhibits strong deviations from local equilibrium at the high density hadron string phase formed during the early stage of the collision. Equilibration of the hadron resonance matter is established in the central cell of volume Vs125 fm3 at later stages, tG10 fmrc, of the resulting quasi-isentropic expansion. The thermodynamical functions in the cell and their time evolution are presented. Deviations of the UrQMD quasi-equilibrium state from the statistical mechanics equilibrium are found. They increase with energy per baryon and lead to a strong enhancement of the pion number density as compared to statistical mechanics estimates at SPS energies. PACS: 25.75.-q; 24.10.Lx; 24.10.Pa; 64.30.qt
KW  - Kollisionen schwerer Ionen
KW  - QMD Modell
KW  - lokales thermodynamisches Gleichgewicht
KW  - Zustandsgleichung
KW  - Nichtgleichgewicht
KW  - Heavy ion collisions
KW  - QMD model
KW  - Local thermodynamical equilibrium
KW  - Equation of state
KW  - Non-equilibrium effects
Y1  - 1999
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/3108
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30-22848
SN  - 0370-2693
VL  - 459
SP  - 660
EP  - 666
PB  - North-Holland Publ.
CY  - Amsterdam
ER  -