TEMPERATURE DEPENDENCE OF THE QCD COUPLING

Abstract

We present a one-loop calculation of a gauge invariant QCD β-function. Using both momentum and temperature renormalization group equations we investigate the running coupling in the magnetic sector as a function of temperature and momentum scale. At fixed momentum scale we find that, in contrast to λɸ4 or QED, high temperature QCD is strongly coupled, even after renormalization group improvement. However, if the momentum scale is changed simultaneously with temperature in a specified manner, the coupling decreases. We also point out in what regime dimensional reduction occurs. Both the cases Nf smaller and larger than [Formula: see text] are discussed.