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

摘要

We study the finite volume effect of the hadronic vacuum polarization contribution to muon g-2, a μ hvp ,in lattice QCD by comparison with two different volumes, L ~(4)= (5.4)~(4)and (8.1)~(4)fm~(4), 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 μ 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 μ 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 μ hvp .