Non-Perturbative Aspects of QCD at High Temperature

Abstract

The studies of QCD at finite temperature have been motivated by the observation that the renormalized coupling constant becomes small at high temperature. This circumstance raised the hope of testing QCD by means of the perturbative expansion and revealing its basic constituents. Soon Monte Carlo calculations indicated a phase transition at high temperature, T = T _c , and the possibility of isolating a single quark in the high temperature phase. There have been a series of papers and models build on the weakly interacting quark-gluon gas and the dynamics of the high temperature phase of QCD seems to be a well understood and closed subjects for a number of researchers. The goal of this contribution is to emphasis that we are far from the understanding of the high temperature phase which is not at all ‘more perturbative’ than the hadronic vacuum of QCD.