Finite-volume correction on the hadronic vacuum polarization contribution to muon g-2 in lattice QCD

TL;DR

This study quantifies finite-volume effects on the hadronic vacuum polarization contribution to muon g-2 in lattice QCD, demonstrating that larger volumes reduce systematic uncertainties in the calculation.

Contribution

It provides a detailed analysis of finite-volume corrections at near-physical pion mass using two different lattice volumes and advanced noise reduction techniques.

Findings

Finite-volume correction is approximately 10(26)×10^{-10} for the light quark contribution.

Larger lattice volume reduces finite-volume effects on $a_\mu^{\rm hvp}$.

Comparison with chiral perturbation theory supports the correction estimates.

Abstract

We study the finite-volume correction on the hadronic vacuum polarization contribution to the muon g-2 ($a_\mu^{\rm hvp}$) in lattice QCD at (near) physical pion mass using two different volumes: $(5.4~{\rm fm})^4$ and $(8.1~{\rm fm})^4$. We use an optimized AMA technique for noise reduction on $N_f=2+1$ PACS gauge configurations with stout-smeared clover-Wilson fermion action and Iwasaki gauge action at a single lattice cut-off $a^{-1}=2.33$ GeV. The calculation is performed for the quark-connected light-quark contribution in the isospin symmetric limit. We take into account the effects of backward state propagation by extending a temporal boundary condition. In addition we study a quark-mass correction to tune to the exactly same physical pion mass on different volume and compare those correction with chiral perturbation. We find $10(26)\times10^{-10}$ difference for light quark $a_\mu^{\rm hvp}$ between $(5.4~{\rm fm})^4$ and $(8.1~{\rm fm})^4$ lattice in 146 MeV pion.