Lattice calculation of the hadronic leading order contribution to the muon $g-2$

TL;DR

This paper presents a lattice QCD calculation of the hadronic vacuum polarisation contribution to the muon g-2, aiming to reduce uncertainties and clarify the discrepancy with experimental measurements, which could hint at new physics.

Contribution

It provides a detailed lattice QCD computation of $a_0^{ m hvp}$ with improved accuracy and compares results across different groups to address existing uncertainties.

Findings

Progress towards sub-percent precision in $a_0^{ m hvp}$ calculation.

Identification of key conceptual and numerical challenges.

Comparison of lattice results with other research groups.

Abstract

The persistent discrepancy of about 3.5 standard deviations between the experimental measurement and the Standard Model prediction for the muon anomalous magnetic moment, $a_\mu$, is one of the most promising hints for the possible existence of new physics. Here we report on our lattice QCD calculation of the hadronic vacuum polarisation contribution $a_\mu^{\rm hvp}$, based on gauge ensembles with $N_f=2+1$ flavours of O($a$) improved Wilson quarks. We address the conceptual and numerical challenges that one encounters along the way to a sub-percent determination of the hadronic vacuum polarisation contribution. The current status of lattice calculations of $a_\mu^{\rm hvp}$ is presented by performing a detailed comparison with the results from other groups.