Testing the Standard Model with the lepton g-2

by Prof. Massimo Passera (INFN Padua)

Monday 13 Jul 2015, 14:15 → 15:45 Europe/Berlin

3344 (TUM - Physics Department - Garching)

The anomalous magnetic moment of the muon (the muon "g-2") is one of the most celebrated tests of the Standard Model (SM). On the other hand, it is believed that new-physics contributions to the electron g-2 are too small to be relevant and, with this assumption, its measurement is employed to determine the fine-structure constant. I will discuss some recent developments in the long-standing discrepancy between experiment and the Standard Model prediction of the muon g-2 and argue that the electron g-2 may soon be used to probe new physics as well. I will also mention possible methods to improve the present limits on the g-2 of the tau using radiative leptonic tau decays. I will conclude discussing the 3.5 sigma discrepancy which has recently been observed between the SM prediction of the branching ratio $\tau \to e \bar{\nu} \nu \gamma)$ and its measurement at BaBar.