Non-perturbative improvement of stout-smeared three flavour clover fermions

TL;DR

This paper introduces a non-perturbative approach to improve three-flavor lattice QCD simulations using stout-smeared clover fermions, tuning the clover coefficient with the Schrödinger functional method.

Contribution

It presents the first non-perturbative determination of the clover coefficient for stout-smeared three-flavor fermions in lattice QCD.

Findings

Non-perturbative clover coefficient determined using Schrödinger functional.

Comparison with perturbation theory shows deviations.

Critical hopping parameter also obtained.

Abstract

We discuss a 3-flavour lattice QCD action with clover improvement in which the fermion matrix has single level stout smearing for the hopping terms together with unsmeared links for the clover term. With the (tree-level) Symanzik improved gluon action this constitutes the Stout Link Non-perturbative Clover or SLiNC action. To cancel O(a) terms the clover term coefficient has to be tuned. We present here results of a non-perturbative determination of this coefficient using the Schroedinger functional and as a by-product a determination of the critical hopping parameter. Comparisons of the results are made with lowest order perturbation theory.