Universality for a three-parameter mixed action

Abstract

We calculate the bare effective Wilson coupling as a function of the three couplings in the mixed SU(2) lattice gauge theory (without fermions), including Tr U p in the three lowest ( spin 1 2 , 1, 3 2 ) representations, complete to two loops and including some higher-order graphs. The calculation is compatible with the N → ∞ limit. We also examine the phase structure of the theory qualitatively using mean-field techniques. We conjecture that a specific constraint among the couplings provides an improved action, and we present some evidence from Monte Carlo renormalization group results in its favour.