Non-perturbative renormalization of the axial current with dynamical Wilson fermions

TL;DR

This paper introduces a new non-perturbative normalization condition for the axial current in lattice QCD with Wilson fermions, reducing mass effects in chiral extrapolations and providing precise renormalization factors.

Contribution

It proposes a novel normalization condition based on the PCAC relation that improves the accuracy of axial current renormalization in dynamical Wilson fermion simulations.

Findings

The new condition reduces mass effects in the chiral limit.

Calculated Z_A and Z_V for various coupling constants.

Validated the approach with two-flavor improved Wilson fermions.

Abstract

We present a new normalization condition for the axial current, derived from the PCAC relation with non-vanishing quark mass. This condition is expected to reduce mass effects in the chiral extrapolation of the results for the normalization factor Z_A. The application to the two-flavor theory with improved Wilson fermions shows that this expectation is indeed fulfilled. Using the Schroedinger functional setup we calculate Z_A(g_0^2) as well as the vector current normalization factor Z_V(g_0^2) for beta = 6/g_0^2 >= 5.2.