Perturbative renormalisation of quark bilinear operators for overlap fermions with and without stout links and improved gauge action

TL;DR

This paper computes one-loop lattice renormalisation constants for quark operators using overlap fermions with improved gauge actions, including stout smearing, providing numerical Z factors in the  scheme for different parameters.

Contribution

It presents the first perturbative calculation of renormalisation constants for overlap fermions with stout links and improved gauge actions, including numerical results and comparisons of mean field improvements.

Findings

Numerical Z factors in the  scheme at specific  values.

Comparison of tadpole improvement effects on renormalisation constants.

Results applicable for lattice QCD simulations with overlap fermions.

Abstract

We calculate lattice renormalisation constants of local and one-link quark operators for overlap fermions and improved gauge actions in one-loop perturbation theory. For the local operators we stout smear the SU(3) links in the fermionic action. Using the popular tadpole improved L\"uscher-Weisz actions at $\beta=8.45$ and $\beta=8.0$ we present numerical values for the Z factors in the $\bar{MS}$ scheme (partly as function of the stout smearing strength). We compare various levels of mean field (tadpole) improvement which have been applied to our results.