Connected and disconnected contributions to nucleon axial form factors using $N_f=2$ twisted mass fermions at the physical point

TL;DR

This study calculates nucleon axial form factors, including disconnected contributions, using $N_f=2$ twisted mass fermions at the physical pion mass, employing advanced computational techniques to improve accuracy.

Contribution

It provides the first comprehensive analysis of both connected and disconnected contributions to nucleon axial form factors at the physical point with twisted mass fermions.

Findings

Disconnected contributions are significant in the axial form factors.

Advanced deflation and truncated solver methods improve computational efficiency.

Ground-state dominance achieved through summation and two-state fits.

Abstract

We present results on the isovector and isoscalar nucleon axial form factors including disconnected contributions,using an ensemble of $N_f =2$ twisted mass clover- improved Wilson fermions simulated with approximately the physical value of the pion mass. The light disconnected quark loops are computed using exact deflation, while the strange and the charm quark loops are evaluated using the truncated solver method. Techniques such as the summation and the two-state fits have been employed to access ground-state dominance.