Partonic Scattering Cross Sections in the QCD Medium

A medium modified gluon propagator is used to evaluate the scattering cross section for the process gg → gg in the QCD medium by performing an explicit sum over the polarizations of the gluons. We incorporate a magnetic sreening mass from a non perturbative study. It is shown that the medium modified cross section is finite, divergence free, and is independent of any ad-hoc momentum transfer cut-off parameters. The medium modified finite cross sections are necessary for a realistic investigation of the production and equilibration of the minijet plasma expected at RHIC and LHC. PACS: 12.38.Mh; 14.70.Dj; 12.38.Bx; 11.10.Wx Typeset using REVTEX present address: T-8, Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA