Non-perturbative improvement of the axial current for dynamical Wilson fermions

TL;DR

This paper non-perturbatively determines the axial current improvement coefficient cA for dynamical Wilson fermions, using Schrödinger functional boundary conditions and two pseudo-scalar states, estimating a 10% correction to F_PS at beta=5.2.

Contribution

It introduces a non-perturbative method to determine cA with improved Wilson fermions, enhancing accuracy in lattice QCD calculations.

Findings

Estimated correction to F_PS is around 10% at beta=5.2.

Large sensitivity achieved using two pseudo-scalar states.

Formulated improvement condition with Schrödinger functional boundary conditions.

Abstract

A non-perturbative determination of the axial current improvement coefficient cA is performed with two flavors of dynamical improved Wilson fermions and plaquette gauge action. The improvement condition is formulated with Schroedinger functional boundary conditions and enforced at constant physical volume. Large sensitivity is obtained by using two different pseudo-scalar states in the PCAC relation. We estimate the resulting correction to F_PS at beta=5.2 to be around 10%.