Nucleon axial and pseudoscalar form factors from lattice QCD at the physical point

TL;DR

This study calculates nucleon axial and pseudoscalar form factors using lattice QCD with physical quark masses, providing insights into their momentum dependence and validating theoretical relations.

Contribution

First lattice QCD calculation of nucleon form factors at physical quark masses including strange and charm quarks, with comprehensive volume and lattice spacing analysis.

Findings

Form factors consistent with experimental data

Validation of pion pole dominance and PCAC relations

Quantitative assessment of finite volume effects

Abstract

We compute the nucleon axial and induced pseudoscalar form factors using three ensembles of gauge configurations, generated with dynamical light quarks with mass tuned to approximately their physical value. One of the ensembles also includes the strange and charm quarks with their mass close to physical. The latter ensemble has large statistics and finer lattice spacing and it is used to obtain final results, while the other two are used for assessing volume effects. The pseudoscalar form factor is also computed using these ensembles. We examine the momentum dependence of these form factors as well as relations based on pion pole dominance and the partially conserved axial-vector current hypothesis.