Effective dynamics of hot, soft non-Abelian gauge fields: Color conductivity and log(1/α)effects

Bödeker has recently argued that non-perturbative processes in very high temperature non-Abelian plasmas (such as electroweak baryon number violation in the very hot early Universe) are logarithmically enhanced over previous estimates and take place at a rate per unit volume of order ${\alpha }^5{T}^4\ln (1/\alpha )$ for small coupling. We give a simple physical interpretation of Bödeker’s qualitative and quantitative results in terms of Lenz’s Law—the fact that conducting media resist changes in the magnetic field—and earlier authors’ calculations of the color conductivity of such plasmas. In the process, we resolve some confusion in the literature about the value of the color conductivity and present an independent calculation. We also discuss the issue of whether the classical effective theory proposed by Bödeker has a good continuum limit.