Hadronic vacuum polarization for the muon $g-2$ from lattice QCD: Long-distance and full light-quark connected contribution

We present results for the dominant light-quark connected contribution to the long-distance window (LD) of the hadronic vacuum polarization contribution (HVP) to the muon $g-2$ from lattice quantum chromodynamics (QCD). Specifically, with a new determination of the lattice scale on MILC’s physical-mass HISQ ensembles, using the ${\mathrm{\Omega }}^{-}$ baryon mass, we obtain a result of $400.2(2.3{)}_{\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t}}(3.7{)}_{\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t}}[4.3{]}_{\mathrm{t}\mathrm{o}\mathrm{t}\mathrm{a}\mathrm{l}}\times {10}^{-10}$. Summing this result with our recent determinations of the light-quark connected contributions to the short- (SD) and intermediate-distance (W) windows, we obtain a sub-percent precision determination of the light-quark-connected contribution to HVP of $655.5(2.3{)}_{\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t}}(3.9{)}_{\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t}}[4.5{]}_{\mathrm{t}\mathrm{o}\mathrm{t}\mathrm{a}\mathrm{l}}\times {10}^{-10}$. Finally, as a consistency check, we verify that an independent analysis of the full contribution is in agreement with the sum of individual windows. We discuss our future plans for improvements of our HVP calculations to meet the target precision of the Fermilab $g-2$ experiment.