A nonperturbative determination of c_A and the scaling of f_pi and m^{MSbar}

TL;DR

This paper nonperturbatively determines the axial-vector current improvement coefficient c_A and examines its impact on the scaling of f_pi and m^{MSbar}, showing improved scaling behavior with the new c_A values.

Contribution

It provides a nonperturbative calculation of c_A and demonstrates its effect on the scaling of key physical quantities in lattice QCD.

Findings

c_A is close to the 1-loop tadpole-improved perturbative value

Scaling of f_pi and m^{MSbar} is improved with the new c_A values

Results are consistent across a range of beta values from 5.93 to 6.2

Abstract

We calculate the $O(a)$ improvement coefficient for the axial-vector current using the nonperturbative method proposed by the LANL group. Results for the coefficient in the range $\beta=5.93$ to 6.2 are presented. We find $c_A$ is close to the 1-loop tadpole-improved perturbative value. In addition, scaling of the pseudoscalar decay constant and renormalised quark mass is improved compared to that obtained using the (larger) $c_A$ values obtained by the ALPHA collaboration.