A high-precision continuum limit study of the HVP short-distance window

TL;DR

This paper introduces a novel lattice QCD approach to precisely compute the short-distance contribution to the hadronic vacuum polarization part of the muon g-2, avoiding reliance on perturbative QCD.

Contribution

It presents a new method combining quenched and sea-quark continuum extrapolations across many lattice spacings for improved accuracy in HVP short-distance calculations.

Findings

Achieved high-precision continuum limit for HVP short-distance window.

Reduced computational cost by estimating sea-quark effects with fewer ensembles.

Demonstrated the effectiveness of the combined extrapolation approach.

Abstract

The separation of the hadronic vacuum polarization (HVP) contribution to the muon anomalous magnetic moment into Euclidean windows allows for a tailored approach to address the different dominant challenges at short, intermediate, and long distances. We present a novel approach to compute the short-distance window without the need for using perturbative QCD. We combine a quenched continuum extrapolation using 18 lattice spacings ($1.6 \,\text{GeV} \lesssim a^{-1} \lesssim 6.1\,\text{GeV}$) with a separate continuum extrapolation of the sea-quark effects. This method allows for the computationally expensive sea-quark effects to be estimated using only a smaller number of ensembles at coarser lattice spacings, while largely confining the logarithmic dependency of the continuum extrapolation to the quenched component.