EPJ Web of Conferences 175, 06020 (2018)
https://doi.org/10.1051/epjconf/201817506020

Lattice study of finite volume effect in HVP for muon g-2

¹ RIKEN-BNL Research Center, Brookhaven National Laboratory, Upton, NY 11973, USA.
² High Energy Theory Group, Brookhaven National Laboratory, Upton, NY 11973, USA.
³ Center for Computational Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan.
⁴ RIKEN Advanced Institute for Computational Science, Kobe, Hyogo 650-0047, Japan.

^* Speaker, e-mail: shintani@riken.jp

Published online: 26 March 2018

Abstract

We study the finite volume effect of the hadronic vacuum polarization contribution to muon g-2, $a_{\mu }^{\mathrm{hvp}}$,in lattice QCD by comparison with two different volumes, L⁴ = (5.4)⁴ and (8.1)⁴ fm⁴, at physical pion. We perform the lattice computation of highly precise vector-vector current correlator with optimized AMA technique on N_f = 2 + 1 PACS gauge configurations in Wilson-clover fermion and stout smeared gluon action at one lattice cut-off, a⁻¹ = 2.33 GeV. We compare two integrals of $a_{\mu }^{\mathrm{hvp}}$, momentum integral and time-slice summation, on the lattice and numerically show that the different size of finite volume effect appears between two methods. We also discuss the effect of backward-state propagation into the result of $a_{\mu }^{\mathrm{hvp}}$ with the different boundary condition. Our model-independent study suggest that the lattice computation at physical pion is important for correct estimate of finite volume and other lattice systematics in $a_{\mu }^{\mathrm{hvp}}$.