Hadronic vacuum polarization contribution to lepton magnetic moments from lattice QCD

by L. Lellouch (CNRS Marseille, France)

Monday 9 Apr 2018, 14:30 → 16:00 Europe/Rome

Aula Conversi (Dip. di Fisica - Edificio G. Marconi)

At the beginning of this century, the anomalous magnetic moment of the muon, a_\mu=(g_\mu-2)/2, was measured with an incredible precision of 0.54ppm. Since the first results were published, a discrepancy of more than 3 standard deviations has persisted between the standard model (SM) prediction and experiment. At present theoretical and experimental uncertainties are pretty much matched. However, two new experiments are underway, that aim at dividing the experimental error on a_\mu by 4. To leverage these future measurements and possibly claim the presence of new fundamental physics, it is mandatory to reduce and fully control the uncertainties in the SM prediction. After an introduction to the role that anomalous magnetic moments play in testing the SM and a discussion of the current experimental and theoretical status of a_\mu, I will present a complete lattice QCD calculation of the contribution to a_\mu that limits the precision of the SM prediction: the hadronic vacuum polarization contribution.