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

Karsch F, Neuhaus T, Patkos A, Rank J. Gauge boson masses in the 3D, SU(2) gauge-Higgs model. NUCLEAR PHYSICS B. 1996;474(1):217-232.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) x L(z) with L = 4 - 24 and L(z) = 16 - 128