The hadronic light-by-light scattering contribution to the muon anomalous magnetic moment from lattice QCD

TL;DR

This paper presents the first lattice QCD calculation of the hadronic light-by-light scattering contribution to the muon g-2 with systematic error control, providing results consistent with previous models and constraining new physics explanations.

Contribution

It provides a systematically controlled lattice QCD determination of the HLbL contribution to muon g-2, improving precision over prior model-based estimates.

Findings

Calculated a_mu^{HLbL} = 7.87(3.06)(1.77) x 10^{-10}

Results are consistent with previous model estimates

Limits the room for new physics explanations of the muon g-2 discrepancy

Abstract

We report the first result for the hadronic light-by-light scattering contribution to the muon anomalous magnetic moment with all errors systematically controlled. Several ensembles using 2+1 flavors of physical mass M\"obius domain-wall fermions, generated by the RBC/UKQCD collaborations, are employed to take the continuum and infinite volume limits of finite volume lattice QED+QCD. We find $a_\mu^{\rm HLbL} = 7.87(3.06)_\text{stat}(1.77)_\text{sys}\times 10^{-10}$. Our value is consistent with previous model results and leaves little room for this notoriously difficult hadronic contribution to explain the difference between the Standard Model and the BNL experiment.