Valence leading isospin breaking contributions to $a_{\mu}^{\mathrm{HVP-LO}}$

TL;DR

This paper presents a lattice QCD+QED calculation of valence isospin-breaking effects on the leading-order hadronic vacuum polarization contribution to the muon g-2, using the RM123 approach on different volumes.

Contribution

It provides the first preliminary lattice results for valence isospin-breaking corrections to $a_^{ ext{HVP-LO}}$ employing the RM123 method in QCD+QED.

Findings

Preliminary results on two lattice volumes show consistent isospin-breaking effects.

The study advances understanding of isospin-breaking contributions to muon g-2.

Results are obtained at a fixed lattice spacing with ongoing efforts for full precision.

Abstract

By employing the RM123 approach to QCD+QED, we computed the valence quark-connected isospin-breaking corrections to the light, strange and charm contributions at leading order in $\alpha_{\mathrm{em}}$ and $\left(\mu_d-\mu_u\right) / \Lambda_{\mathrm{QCD}}$. Here we report the preliminary results on two different volumes ($L \sim 3.8$ fm and $L \sim 5.1$ fm) and a fixed lattice spacing (corresponding to $a_{\text {isoQCD }} \sim 0.07951(4)$ fm), obtained in the framework of the ongoing computation by ETMC of the leading-order hadronic vacuum polarization (HVP) contribution to the muon anomalous magnetic moment $a_\mu^{\mathrm{HVP}}$ in QCD+QED.