The hadronic vacuum polarization contribution to the muon g-2 from lattice QCD

We present a calculation of the hadronic vacuum polarization contribution to the muon anomalous magnetic moment, alpha(hvp)(mu), in lattice QCD employing dynamical up and down quarks. We focus on controlling the infrared regime of the vacuum polarization function. To this end we employ several complementary approaches, including Pade fits, time moments and the time-momentum representation. We correct our results for fi nitevolume e ff ects by combining the Gounaris-Sakurai parameterization of the timelike pion form factor with the Luscher formalism. On a subset of our ensembles we have derived an upper bound on the magnitude of quark-disconnected diagrams and found that they decrease the estimate for alpha(hvp)(mu) by at most 2%. Our fi nal result is alpha(hvp)(mu) - (654 +/- 32(-23)(+21)). 10(-10), where the first error is statistical, and the second denotes the combined systematic uncertainty. Based on our findings we discuss the prospects for determining alpha(hvp)(mu) with sub-percent precision.