On the significance of new physics in b → sl+l- decays

Motivated by deviations with respect to Standard Model predictions in b -> sl(+)l(-) decays, we evaluate the global significance of the new physics hypothesis in this system by including the look-elsewhere effect for the first time. We estimate the trial-factor with pseudo-experiments and find that it can be as large as seven. We calculate the global significance for the new physics hypothesis by considering the most general description of a non-standard b -> sl(+)l(-) amplitude of short-distance origin. Theoretical uncertainties are treated in a highly conservative way by absorbing the corresponding effects into a redefinition of the Standard Model amplitude. Using the most recent measurements of LHCb, ATLAS and CMS, we obtain the global significance to be 4.3 standard deviations. (C) 2021 The Authors. Published by Elsevier B.V.

Automated summary

The study evaluates the global significance of the new physics hypothesis in b -> sl(+)l(-) decays, incorporating the look-elsewhere effect for the first time. The trial-factor is estimated with pseudo-experiments, showing it can be as large as seven. The global significance is calculated to be 4.3 standard deviations by considering the most general description of a non-standard b -> sl(+)l(-) amplitude of short-distance origin and treating theoretical uncertainties in a highly conservative manner.