Local thermodynamic properties and equilibration in relativistic heavy-ion collisions

Abstract

We evaluate the local energy-momentum tensor T μv ( x) within the relativistic BUU approach based on scalar and vector meson exchange and study equilibration phenomena for 93Nb→ 93 Nb at 1 A GeV. We use three parameter sets of the lagrangian density reflecting different equations of state (EOS). Local equilibrium times and pressures P i ( x) are found to sizeably depend on the EOS, especially on the momentum-dependent forces employed. An anisotropy of the pressure tensor remains in the central overlap region even for small impact parameters. This raises severe doubts on local equilibrium concepts like temperature etc. as used in hydrodynamical approaches.