One-loop renormalisation of quark bilinears for overlap fermions with improved gauge actions

Abstract

We compute lattice renormalisation constants of local bilinear quark operators for overlap fermions and improved gauge actions. Among the actions we consider are the Symanzik, Lüscher-Weisz, Iwasaki and DBW2 gauge actions. The results are given for a variety of $\rho$ parameters. We show how to apply mean field (tadpole) improvement to overlap fermions. The question, what is a good gauge action, is discussed from the perturbative point of view. Finally, we show analytically that the gauge dependent part of the self-energy and the amputated Green functions are independent of the lattice fermion representation, using either Wilson or overlap fermions.

Comments: 38 pages, 5 figures, v2: Numbers in Tables 1-4,7-10 corrected, Figs. 4,5 updated, 2 misprints in (A.2), (A.4) corrected