Wilson fermions with chirally twisted mass

TL;DR

This paper discusses a lattice QCD formulation using Wilson fermions with a chirally twisted mass, which avoids zero modes and simplifies renormalization, showing promising initial results.

Contribution

It introduces a chirally twisted mass approach for Wilson fermions that improves numerical stability and renormalization in lattice QCD simulations.

Findings

No spurious zero modes at finite quark mass

Simplified renormalization and O(a) improvement

Encouraging initial results in quenched approximation

Abstract

Lattice formulations of QCD with Wilson fermions and a chirally twisted quark mass matrix provide an attractive framework for non-perturbative numerical studies. Owing to reparameterization invariance, the limiting continuum theory is just QCD. No spurious quark zero modes, which are responsible for the problem with exceptional configurations, can occur at finite values of the quark mass. Moreover, the details of the lattice formulation can be adjusted so as to simplify the renormalization and the O($a$) improvement of several quantities of phenomenological relevance. The first exploratory studies in the quenched approximation yield very encouraging results.