Calculating the QED correction to the hadronic vacuum polarisation on the lattice

TL;DR

This paper reports on lattice QCD calculations of QED corrections to the hadronic vacuum polarization, crucial for refining the theoretical prediction of the muon's anomalous magnetic moment, g-2.

Contribution

It presents the first lattice QCD calculation of QED corrections to the hadronic vacuum polarization in a Dashen scheme with physical quark masses.

Findings

Results obtained at three lattice spacings.

Analysis includes physical Nf=2+1+1 ensembles.

Provides data for isospin-breaking corrections.

Abstract

Isospin-breaking corrections to the hadron vacuum polarization component of the anomalous magnetic moment of the muon are needed to ensure the theoretical precision of $g_\mu -2$ is below the experimental precision. We describe the status of our work calculating, using lattice QCD, the QED correction to the light and strange connected hadronic vacuum polarization in a Dashen scheme. We report results using physical $N_f=2+1+1$ HISQ ensembles at three lattice spacings and three heavier-than-light valence quark masses.