On the significance of new physics in b → sℓ+ℓ− decays
Gino Isidori, Davide Lancierini, Patrick Owen, Nicola Serra
Abstract
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.