Pion-pole contribution to HLbL from twisted mass lattice QCD at the physical point

TL;DR

This paper uses twisted mass lattice QCD at the physical point to compute the pion transition form factor, aiming to accurately estimate the pion-pole contribution to the muon's anomalous magnetic moment.

Contribution

First direct lattice QCD calculation of the pion transition form factor at the physical point for the muon g-2 contribution.

Findings

Initial estimate of the pion-pole contribution to muon g-2

Computed the form factor with pion at rest setup

Demonstrated feasibility of direct lattice calculation at physical parameters

Abstract

We report on our computation of the pion transition form factor ${\cal F}_{P\rightarrow \gamma^*\gamma^*}$ from twisted mass lattice QCD in order to determine the numerically dominant light pseudoscalar pole contribution in the hadronic light-by-light scattering contribution to the anomalous magnetic moment of the muon $a_\mu =(g-2)_\mu$. The pion transition form factor is computed directly at the physical point. We present first results for our estimate of the pion-pole contribution with kinematic setup for the pion at rest.