Pressure isotropization of an equilibrating quark-gluon plasma
  Pressure isotropization of an equilibrating quark-gluon plasma produced in relativistic heavy ion collisions is studied within the framework of a multi-phase transport model (AMPT). The time evolution of the bulk properties of the quark-gluon plasma is found to depend on its expansion dynamics and hadronization scheme as well as the scattering cross sections among quarks and gluons. It is further found that the pressure isotropy of the produced quark-gluon plasma can only be achieved temporarily, indicating that there is only partial thermalization during the time evolution of the quark-gluon plasma. 
Bin Zhang (1), Lie-Wen Chen (2), Che Ming Ko (3) ((1) Arkansas State   U, (2) Shanghai Jiaotong U, (3) Texas A-M)