The nucleon axial charge in full lattice QCD

TL;DR

This paper reports a lattice QCD calculation of the nucleon axial charge across various pion masses and volumes, demonstrating small finite volume effects and close agreement with experimental values within statistical errors.

Contribution

First calculation of the nucleon axial charge using light pion masses and large volumes with domain wall and staggered quarks, incorporating finite volume chiral perturbation theory.

Findings

Finite volume effects are small for the studied volumes.

Calculated axial charge agrees with experimental values within 7% statistical error.

Pion masses as light as 354 MeV used in the simulation.

Abstract

The nucleon axial charge is calculated as a function of the pion mass in full QCD. Using domain wall valence quarks and improved staggered sea quarks, we present the first calculation with pion masses as light as 354 MeV and volumes as large as (3.5 fm)^3. We show that finite volume effects are small for our volumes and that a constrained fit based on finite volume chiral perturbation theory agrees with experiment within 7% statistical errors.