QED and strong isospin corrections in the hadronic vacuum polarization contribution to the anomalous magnetic moment of the muon

TL;DR

This paper discusses the inclusion of QED and strong-isospin-breaking effects in the precise calculation of the hadronic vacuum polarization contribution to the muon g-2, improving the accuracy of theoretical predictions.

Contribution

It introduces a method to incorporate isospin-breaking effects by expanding correlation functions, enabling more efficient and precise calculations for muon g-2.

Findings

QED and strong-isospin-breaking effects are successfully included in the calculation.

The approach improves resource distribution for more accurate results.

Enhanced precision in the hadronic vacuum polarization contribution to muon g-2.

Abstract

Recently, the Budapest-Marseille-Wuppertal collaboration achieved sub-percent precision in the evaluation of the lowest-order hadronic vacuum polarization contribution to the muon $g_\mu-2$ (arXiv:hep-lat/2002.12347v3). At this level of precision, isospin-symmetric QCD is not sufficient. In this contribution we review how QED and strong-isospin-breaking effects have been included in our work. Isospin breaking is implemented by expanding the relevant correlation functions to second order in the electric charge $e$ and to first order in $m_u-m_d$. The correction terms are then computed using isospin-symmetric configurations. The choice of this approach allows us to better distribute the available computing resources among the various contributions.