Title: New physics in B decays? Challenges to Lepton Flavor Universality from LHCb and the B factories
Abstract: Since the establishment of the Standard Model (SM) many decades ago, the three types of charged leptons (electron, muon, and tau) have been seen as doppelgängers of each other in everything but their readings on the scale. That is, the SM interactions of the three lepton families with other particles differ only because of their different masses. This resulting (accidental) symmetry is known as Lepton Flavor Universality (LFU). Since 2012, however, a series of measurements of decays involving tree-level b → cτν and loop-level b → sℓℓ transitions (the so-called "B anomalies") have repeatedly hinted at the possibility that lepton universality may be, in fact, violated. This pattern was reinforced in March 2021 when LHCb reported the first deviation from the SM by more than 3σ in a single LFU observable, one which is affected by negligible theoretical uncertainties. In this talk I will go over the current status of LFU measurements as well as their compatibility with exotic leptoquarks, and will briefly review the prospects for the upcoming LHCb and Belle II datasets to resolve the anomalies one way or another.
Refreshments will be offered at 3:30 p.m. in the small plaza outside the lecture room doors (facing Regents Drive and the Plant Sciences Bldg.)