Gluon plasmon frequency near the light-cone
  Thermal perturbation theory based on the resummation scheme by Braaten and Pisarski suffers from unscreened collinear singularities whenever outer momenta become light-like. A recently proposed improvement of the hard thermal loops by an additional resummation of an asymptotic mass promises to solve this problem. Here we present a detailed investigation of the next-to-leading order plasmon self-energy. It demonstrates the applicability and consistency of the improved scheme. 
Fritjof Flechsig