Non-equilibrium approaches to the pre-thermal and post-hadronisation stages of A+A collisions

Abstract

The results related to non-equilibrium phenomena at the very early and late stages of the processes of A+A collisions are presented. A good description of the hadron momentum spectra as well as pion and kaon interferometry data at RHIC is reached within the realistic dynamical picture of A+A collisions: HydroKinetic Model (HKM). The model accumulates the following features: not too early thermalization time; $\tau \ge 1$ fm/c; a developing of the pre-thermal transverse flows; the effectively more hard, than in the case of chemical equilibrium, equation of state of expanding chemically non-equilibrated multi-hadronic gas; a continuous non-equilibrated emission of hadrons. All these factors lead to a good description of the mentioned RHIC data, in particular, the observed $R_{out}/R_{side}$ ratios, solving, therefore, the HBT puzzle in detailed realistic model.

Comments: 10 pages, 2 figures; talks given at XXXIX International Symposium on Multiparticle Dynamics, Gomel, Belarus September 4-9, 2009 and ECT Workshop on flows and dissipation in ultrarelativistic A+A collisions September 14-18, 2009