COLLECTIVE THERMALIZATION IN QUARK-GLUON PLASMA

A very important question in ultrarelativistic heavy ion collisions is that of thermalization of the high energy density quark gluon plasma formed in the central rapidity region. Different approaches have been adopted by various authors to study this thermalization problem. These include phenomenological string and capacitor plate models, perturbat ive QCD based parton cascade models and the classical non-perturbative approach. In this paper we briefly review the earlier studies and dis cuss our work which emphasizes the role of non-perturbative collective effects (classical chaos) in the thermalization of the plasma. In par ticular, using classical equations of motion of a coloured parton in s elf-consistent colour fields, we have carried out a 1 + 1 dimensional simulation of coloured partonic matter. We find that in certain parame ter domains, the system exhibits chaotic behaviour in non-abelian plas ma oscillations, which then leads to thermalization of the plasma.