Muon g-2 with overlap valence fermion
Résumé
We present a lattice calculation of the leading order (LO) hadronic vacuum polarization (HVP) contribution to the muon anomalous magnetic moment for the connected light and strange quarks, $a^{\rm W}_{{\rm con}, l\,/s}$ in the widely used window $t_0=0.4~\mathrm{fm}$, $t_1=1.0~\mathrm{fm}$, $\Delta=0.15~\mathrm{fm}$, and also of $a^{\rm S}_{{\rm con}, l\,/s}$ in the short distance region. We use the overlap fermion on 4 physical-point ensembles. Two 2+1 flavors ensembles use the domain wall fermion (DWF) and Iwasaki gauge actions at $a = 0.084$ and 0.114 fm, and two 2+1+1 flavors ensembles use the highly-improved-staggered-quark (HISQ) and Symanzik gauge actions at $a = 0.088$ and 0.121 fm. They have incorporated infinite volume corrections from 3 additional DWF ensembles at ${\rm L}$ = 4.8, 6.4 and 9.6 fm and physical pion mass. For the $a^{\rm W}_{{\rm con}, l}$, we find that our results on the two smaller lattice spacings are consistent with those using the unitary setup, but those at the two coarser lattice spacings have obviously small differences compared to the unitary ones.