Evading the Infrared Problem of Thermal QCD

Abstract

Due to asymptotic freedom, QCD is guaranteed to be accessible to perturbative methods at asymptotically high temperatures. However, in 1979 Linde has pointed out the existence of an "infrared wall", beyond which an infinite number of Feynman diagrams contribute. Following a proposal by Braaten and Nieto, it is shown explicitly how the limits to computability that this infrared problem poses can be overcome in the framework of dimensionally reduced effective theories.