QCD corrections to the electroweak sphaleron rate

Abstract

The electroweak sphaleron rate in the high temperature phase of the Standard Model is inversely proportional to the weak-isospin conductivity. So far, only electroweak interactions were included in its computation. Here we take into account quark scattering through strong interactions at leading-log order. These reduce the quark contribution to the conductivity by up to 15 %, and the total conductivity by up to 6 %.

Comments: 27 pages, 4 figures, 1 table. Added discussion of the size of the QCD correction and of possible higher order effects