The role of the gluonic $gg\leftrightarrow{ggg}$ interactions in early thermalization in ultrarelativistic heavy-ion collisions

We “quantify” the role of elastic as well as inelastic pQCD processes in kinetic equilibration within a pQCD inspired parton cascade. The contributions of different processes to kinetic equilibration are manifested by the transport collision rates. We find that in a central Au+Au collision at RHIC energy pQCD bremsstrahlung processes are much more efficient for momentum isotropization compared to elastic scatterings. For the parameters chosen the ratio of their transport collision rates amounts to 5:1. PACS  05.60.-k, 25.75.-q, 24.10.Lx