Lattice Determination of the Hadronic Contribution to the Muon $g-2$ using Dynamical Domain Wall Fermions

TL;DR

This paper calculates the leading hadronic contribution to the muon's magnetic moment using lattice QCD with domain wall fermions, achieving results consistent with previous estimates and proposing improvements for future precision.

Contribution

It introduces a robust fitting technique for lattice data and provides a new calculation of the hadronic contribution to muon g-2 with controlled uncertainties.

Findings

Result a_μ^{(2)had} = 641(33)(32) x 10^{-10} at physical quark masses

Methodology for fitting electromagnetic correlators with vector dominance models

Agreement with previous experimental and theoretical estimates

Abstract

We present a calculation of the leading order hadronic contribution to the anomalous magnetic moment of the muon for a dynamical simulation of 2+1 flavour QCD using domain wall fermions. The electromagnetic 2-point function is evaluated on the RBC-UKQCD lattice gauge configurations and this is fitted to a continuous form motivated by models of vector dominance. We determine a robust and reliable technique for performing this fit, allowing us to extract the most accurate results possible from our ensembles. This combined with data at very light quark masses produces the result a_\mu^{(2)had}=641(33)(32) x 10^{-10} at the physical point, where the first uncertainty is statistical, and the second is an estimate of systematics, which is in agreement with previous results. We outline various methods by which this calculation can and will be improved in order to compete with the accuracy of alternative techniques of deducing this quantity from experimental scattering data.