Non-perturbative improvement of the axial current with three dynamical flavors and the Iwasaki gauge action

TL;DR

This paper non-perturbatively determines the improvement coefficient c_A in three-flavor lattice QCD with the Iwasaki gauge action, reducing discretization errors in the axial current for more accurate simulations.

Contribution

It provides a precise non-perturbative calculation of c_A, enhancing the accuracy of lattice QCD computations involving the axial current with three dynamical flavors.

Findings

c_A determined non-perturbatively with good sensitivity

Results combined with perturbative expansion for improved accuracy

c_A known precisely for 1/a  1.6 GeV

Abstract

We perform a non-perturbative determination of the improvement coefficient c_A to remove O(a) discretization errors in the axial vector current in three-flavor lattice QCD with the Iwasaki gauge action and the standard O$(a)$-improved Wilson quark action. An improvement condition with a good sensitivity to c_A is imposed at constant physics. Combining our results with the perturbative expansion, c_A is now known rather precisely for 1/a \gtrsim 1.6 GeV.