Gauge boson masses in the 3D, SU(2) gauge-Higgs model

Abstract

We study gauge boson propagators in the symmetric and symmetry broken phases of the 3D, SU(2) gauge-Higgs model. Correlation functions for the gauge fields are calculated in Landau gauge. They are found to decay exponentially at large distances leading to a non-vanishing mass for the gauge bosons. We find that the W-boson screening mass drops in the symmetry broken phase when approaching the critical temperature. In the symmetric phase the screening mass stays small and is independent of the scalar-gauge coupling (the hopping parameter). Numerical results coincide with corresponding calculations performed for the pure gauge theory. We find m w = 0.35(1) g 2 T in this phase which is consistent with analytic calculations based on gap equations. This is, however, significantly smaller than masses extracted from gauge-invariant vector boson correlation functions. As internal consistency check we also have calculated correlation functions for gauge-invariant operators leading to scalar and vector boson masses. Finite lattice size effects have been systematically analyzed on lattices of size L 2 × L z with L = 4 – 24 and L z = 16 – 128.