The relevant scale parameter in the high temperature phase of QCD
Abstract
We introduce the running coupling constant of QCD in the high temperature phase, overlineg^{2}(T) , through a renormalization scheme where the dimensional reduction is optimal at the oneloop level. We then calculate the relevant scale parameter, Λ_{T}, which characterizes the running of overlineg^{2}(T) with T, using the background field method in the static sector. It is found that Λ _{T}/Λ=e( ^{γE+ {1}/{22}})/(4π) ≈ 0.148 . We further verify that the coupling overlineg^{2}(T) is also optimal for lattice perturbative calculations. Our result naturally explains why the high temperature limit of QCD sets in at temperatures as low as a few times the critical temperature. In addition, our Λ_{t} agrees remarkably well with the scale parameter determined from the lattice measurement of the spatial string tension of the SU(2) gauge theory at high T.
 Publication:

Nuclear Physics B
 Pub Date:
 February 1995
 DOI:
 10.1016/05503213(95)00007F
 arXiv:
 arXiv:hepph/9411293
 Bibcode:
 1995NuPhB.438...54H
 Keywords:

 High Energy Physics  Phenomenology;
 High Energy Physics  Lattice;
 Nuclear Theory
 EPrint:
 13 pages, RevTeX 3.0, no figures. Full postscript version available via anonymous ftp (192.84.132.4) at ftp://risc0.ca.infn.it/pub/private/lissia/infncath9424.ps