arXiv:hep-ph/0010172·v1·High Energy Physics — Phenomenology
Equation of state of resonance-rich matter in the central cell in heavy-ion collisions at =200 AGeV
L.V.Bravina (1,2)🇩🇪 · E.E.Zabrodin (1,2)🇩🇪 · S.A.Bass (3)🇺🇸 · M.Bleicher (4)🇺🇸 · M.Brandstetter(5)🇩🇪 · A. Faessler(1)🇩🇪 · C.Fuchs(1)🇩🇪 · W.Greiner(5)🇩🇪 · S.Soff(6)🇩🇪 · H.Stoecker(5) (1-Institute for Theoretical Physics, University of Tueubingen, Germany; 2-Institute for Nuclear Physics, Moscow State University, Russia; 3-National Superconducting Cyclotron Laboratory, Michigan State University, USA; 4-Nuclear Science Division, Lawrence Berkeley Laboratory, USA; 5-Institute for Theoretical Physics, University of Frankfurt, Germany; 6-Gesellschaft fuer Schwerionenforschung, Darmstadt, Germany)🇩🇪
Abstract
The equilibration of hot and dense nuclear matter produced in the central cell of central Au+Au collisions at RHIC ( AGeV) energies is studied within a microscopic transport model. The pressure in the cell becomes isotropic at fm/ after beginning of the collision. Within the next 15 fm/ the expansion of matter in the cell proceeds almost isentropically with the entropy per baryon ratio , and the equation of state in the plane has a very simple form, . Comparison with the statistical model of an ideal hadron gas indicates that the time fm/c may be too short to reach the fully equilibrated state. Particularly, the creation of long-lived resonance-rich matter in the cell decelerates the relaxation to chemical equilibrium. This resonance-abundant state can be detected experimentally after the thermal freeze-out of particles.
Comments: LATEX, 21 pages incl. 7 figures