# Nucleon axial form factors using lattice QCD simulations with a physical value of the pion mass

## TL;DR

This paper reports on lattice QCD simulations at the physical pion mass to compute nucleon axial form factors, including isovector, isoscalar, strange, and charm contributions, highlighting significant disconnected quark loop effects.

## Contribution

It introduces a novel lattice QCD approach with deflation techniques to accurately evaluate disconnected contributions to nucleon axial form factors at the physical pion mass.

## Key findings

- Disconnected quark loops are non-zero and large for the induced pseudo-scalar form factor.
- The study provides detailed isovector, isoscalar, strange, and charm axial form factors.
- Results improve understanding of nucleon structure and quark flavor contributions.

## Abstract

We present results on the nucleon axial and induced pseudo-scalar form factors using an ensemble of two degenerate twisted mass clover-improved fermions generated at the physical value of the pion mass. We evaluate the isovector and the isoscalar, as well as, the strange and the charm axial form factors. The disconnected contributions are evaluated using recently developed methods that include deflation of the lower eigenstates, allowing us to extract the isoscalar, strange and charm axial form factors. We find that the disconnected quark loop contributions are non-zero and particularly large for the induced pseudo-scalar form factor.