Transport coefficients and the 2PI effective action in the large N limit

Abstract

We discuss the computation of transport coefficients in large N_f QCD and the O(N) model for massive particles. The calculation is organized using the 1/N expansion of the 2PI effective action to next-to-leading order. For the gauge theory, we verify gauge fixing independence and consistency with the Ward identity. In the gauge theory, we find a nontrivial dependence on the fermion mass.

Comments: 10 pages, based on presentations at Strong and Electroweak Matter (SEWM04), Helsinki, Finland, June 16-19 2004, and the Workshop on QCD in Extreme Environments, Argonne National Laboratory, USA, June 29-July 3 2004