Flavour anomalies after the RK* measurement

The LHCb measurement of the mu/e ratio R-K* indicates a deficit with respect to the Standard Model prediction, supporting earlier hints of lepton universality violation observed in the R-K ratio. We show that the R-K and R-K* ratios alone constrain the chiralities of the states contributing to these anomalies, and we find deviations from the Standard Model at the 4 sigma level. This conclusion is further corroborated by hints from the theoretically challenging b -> s mu(+),mu(-) distributions. Theoretical interpretations in terms of Z' lepto-quarks, loop mediators, and composite dynamics are discussed. We highlight their distinctive features in terms of the chirality and flavour structures relevant to the observed anomalies.