Debye Screening Mass from effective Potentials in Lattice Gauge Theory

In this paper, we use a definition of the Debye screening mass in SU(2) pure gauge theory at high temperature in 3+1 dimensions, that makes use of the walls between different $Z_2$ domains. We show, that this definition enables us to unambiguously obtain the Debye Screening mass from the curvature of the effective potential for the Polyakov loops calculated in the modified axial gauge. Using an approach on asymmetric lattices, we obtain numerical values for the Debye mass and compare them to perturbative as well as Monte-Carlo results. Our resulting Debye-Masses are significantly higher than the one-loop perturbative one. They are within the errors in agreement with those obtained by Monte-Carlo methods. Open questions are discussed.