Hadronic vacuum polarization for the muon $g-2$ from lattice QCD: Long-distance and full light-quark connected contribution

TL;DR

This paper provides a high-precision lattice QCD calculation of the dominant light-quark connected contribution to the hadronic vacuum polarization part of the muon g-2, crucial for understanding potential new physics.

Contribution

It presents a new determination of the light-quark connected contribution to HVP using improved lattice scale setting and combines results across different distance windows for enhanced precision.

Findings

Achieved a total light-quark connected HVP contribution of 655.5(4.5)×10^{-10}.

Confirmed consistency between full and windowed analyses of the HVP contribution.

Enhanced the precision of lattice QCD calculations relevant for the muon g-2 experiment.

Abstract

We present results for the dominant light-quark connected contribution to the long-distance window (LD) of the hadronic vacuum polarization contribution (HVP) to the muon $g-2$ from lattice quantum chromodynamics (QCD). Specifically, with a new determination of the lattice scale on MILC's physical-mass HISQ ensembles, using the $\Omega^-$ baryon mass, we obtain a result of $400.2(2.3)_{\mathrm{stat}}(3.7)_{\mathrm{syst}}[4.3]_{\mathrm{total}} \times 10^{-10}$. Summing this result with our recent determinations of the light-quark connected contributions to the short- (SD) and intermediate-distance (W) windows, we obtain a sub-percent precision determination of the light-quark-connected contribution to HVP of $655.5(2.3)_{\mathrm{stat}}(3.9)_{\mathrm{syst}}[4.5]_{\mathrm{total}} \times 10^{-10}$. Finally, as a consistency check, we verify that an independent analysis of the full contribution is in agreement with the sum of individual windows. We discuss our future plans for improvements of our HVP calculations to meet the target precision of the Fermilab $g-2$ experiment.