The quest for precision in b -> s ll decays

Tuesday, 19 November 2024 at 11:15

The B-physics experiments, LHCb, Belle-II and now CMS, are reporting intriguing results in the decay of a b-quark into an s-quark and two leptons. Taken together, these results suggest a deviation from the predictions of the Standard Model of more than 5 standard deviations. These predictions are notoriously difficult, however, because they involve non-perturbative hadronic quantities that cannot be obtained from first principles. I will first present some new parameterizations based on analyticity, unitarity, and so-called dispersive bounds that allow to constrain some of these quantities. I will then discuss some new ideas to go beyond the current limitations and reduce the theoretical uncertainties even further.