Toward parton equilibration with
improved parton
interaction matrix elements, B. Zhang, Arkansas
State
University, U.S.A. − The Quark-Gluon Plasma can be produced
in high
energy heavy ion collisions and how it equilibrates is important
for the
extraction of the properties of strongly interacting matter.
A radiative
transport model can be used to reveal interesting characteristics
of
Quark-Gluon Plasma thermalization. For
example,
screened parton interactions always lead to partial pressure
isotropization. Systems
with different
initial pressure anisotropies evolve toward the same asymptotic
evolution. In
particular, radiative processes are crucial
for the chemical equilibration of the system. Matrix elements
under the soft
and collinear approximation for these processes as was first
derived by Gunion
and Bertsch are widely used. A
different
approach is to start with the exact matrix element for the
2<->3
processes as was first conjectured by Parke and Taylor. General features of this
approach will be
reviewed and the results will be compared with the Gunion-Bertsch
results. We will
comment on the possible implications
of the exact matrix element approach on Quark-Gluon Plasma
thermalization.