Equilibrium and equilibration in a gluon plasma with improved matrix elements

Abstract

The hot and dense matter created in the early stage of a relativistic heavy ion collision is composed mainly of gluons. Radiative processes can play an important role for the thermalization of such partonic systems. The simplest parton number changing processes are commonly described by the Gunion-Bertsch formula. We show that the cross section from the exact matrix element for the lowest order radiative process could be significantly smaller than that based on the Gunion-Bertsch formula. In light of this, we discuss the role of radiative processes on the equilibrium and equilibration of a gluon plasma.