Title: "RK, RD(*), and their cousins: update on the continued challenges to lepton flavor universality"
Abstract: A cornerstone of the Standard Model (SM) is the universality of the electroweak couplings to the three lepton families. This results in an accidental lepton flavor symmetry that is broken in the SM only due to the different masses of the charged leptons. However, since 2012, 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 a measurement of RK that for the first time deviated 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 the current status of LFU measurements with particular emphasis on the most recent ones, and will briefly review the prospects for the upcoming LHCb and Belle II datasets to resolve the anomalies one way or another.