We present a progress report on the Fermilab Lattice, HPQCD, and MILC Collaborations’ calculation of the hadronic vacuum polarization contribution to the muon anomalous magnetic moment (g-2). This calculation is needed in order to make full use of the upcoming Fermilab and J-PARC experiments to measure the muon g-2 to higher precision and improve the sensitivity to physics beyond the Standard Model. We are using the method introduced by HPQCD that employs time moments of current-current correlators to remove large statistical and systematic errors associated with the extrapolation to zero momentum. Our calculation is being performed directly at the physical light-quark masses, and employs multiple spatial volumes and lattice spacings down to about 0.09 fm. We are also working on direct calculations of the isospin-breaking, electromagnetic, and quark-disconnected contributions. Our target is to reduce the error in the hadronic vacuum polarization contribution to the muon g-2, including all systematic uncertainties, to around 1% within the next one or two years.

Hadron Structure