Jan 10 – 14, 2022
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On the significance of the flavour anomalies

Jan 10, 2022, 4:21 PM
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Davide Lancierini (University of Zurich (CH))


A coherent pattern of deviations from Standard Model predictions has been observed in $b$-hadron decays of the type $b\to s\ell^+\ell^-$. These deviations seem to indicate
the existence of a new fundamental interaction that breaks lepton flavour universality (LFU).
We discuss the Look Elsewhere Effect in estimating the significance
of this hypothesis and, more generally, any new physics of short-distance origin
in this system, by combining different observables.
We show that even using a very conservative approach towards theory uncertainties, and very general new-physics hypotheses, a significance of about 4 sigma is obtained.
In view of future experimental tests of LFU in these channels, we present a general expression that allows one to include in the fit of modified Wilson coefficients also observables such as $R_{pK}$, $R_{K\pi}$ and $R_{K\pi\pi}$, for which the form factors are unknown. We show that the inclusion of such observables can have a dramatic effect on the new physics significance.

Primary authors

Abhijit Mathad (Universitaet Zuerich (CH)) Nicola Serra (Universitaet Zuerich (CH)) Gino Isidori (Universitaet Zuerich (CH)) Patrick Haworth Owen (Universitaet Zuerich (CH)) Rafael Silva Coutinho (Universitaet Zuerich (CH))

Presentation materials