Various definitions for the QCD Debye mass and its evaluation are reviewed in a non-perturabtive framework for the study of screening of general static sources. While it is possible to perturbatively integrate over scales ∼ T and thus construct a 3d effective theory, the softer scales ∼ gT and ∼ gT are strongly coupled for temperatures < ∼ 10 GeV and require lattice simulations. Within the effe...

We present an alternative way to calculate the screening of the static potential between two charges in (non)abelian gauge theories at high temperatures. Instead of a loop expansion of a gauge boson self-energy, we evaluate the energy shift of the vacuum to order e 2 after applying an external static magnetic field and extract a temperature-and momentum-dependent dielectric permittivity. The Ha...