Axial Nucleon form factors from lattice QCD

TL;DR

This paper computes nucleon axial form factors using lattice QCD with twisted mass fermions, analyzing volume and cut-off effects, and extrapolates results to compare with experimental data.

Contribution

It provides new lattice QCD results for nucleon axial form factors, including continuum and physical pion mass extrapolations, with detailed analysis of systematic effects.

Findings

Axial charge obtained in the continuum limit.

Results consistent with experimental measurements.

Systematic effects from volume and lattice spacing analyzed.

Abstract

We present results on the nucleon axial form factors within lattice QCD using two flavors of degenerate twisted mass fermions. Volume effects are examined using simulations at two volumes of spatial length $L=2.1$ fm and $L=2.8$ fm. Cut-off effects are investigated using three different values of the lattice spacings, namely $a=0.089$ fm, $a=0.070$ fm and $a=0.056$ fm. The nucleon axial charge is obtained in the continuum limit and chirally extrapolated to the physical pion mass enabling comparison with experiment.