Transverse interactions and transport in relativistic quark-gluon and electromagnetic plasmas

Abstract

In calculating the transport properties of relativistic electromagnetic or quark-gluon plasmas microscopically, one encounters the problem of divergent constituent cross sections arising from the exchange of transverse photons or gluons. Inclusion of Landau damping of the virtual quanta exchanged provides an effective long-wavelength cutoff. Dominance of Landau damping over a possible magnetic mass in QCD is demonstrated in the weak-coupling limit. The viscosities of a pure gluon plasma and a quark-gluon plasma are calculated in weak coupling from a variational solution to the Boltzmann equation.