Jul 10 – 17, 2019
Europe/Brussels timezone

Implications for New Physics in $b\to s \mu\mu$ transitions after recent measurements by Belle and LHCb

Jul 13, 2019, 11:20 AM
Campus Ledeganck - Aud. 5 (Ghent)

Campus Ledeganck - Aud. 5


Parallel talk Flavour Physics and CP Violation Flavour Physics and CP Violation


Dr Dinesh Kumar (National Centre for Nuclear Research, Warsaw)


We present a Bayesian analysis of the implications for new physics in semileptonic $b\to s$ transitions after including new measurements of $R_K$ at LHCb and new determinations of $R_{K^*}$ and $R_{K^{*+}}$ at Belle. We perform global fits with 1, 2, 4, and 8 input Wilson coefficients, plus one CKM nuisance parameter to take into account uncertainties that are not factorizable. We infer the 68\% and 95.4\% credibility regions of the marginalized posterior probability density for all scenarios and perform comparisons of models in pairs by calculating the Bayes factor given a common data set. We then proceed to analyzing a few well-known BSM models that can provide a high energy framework for the EFT analysis. These include the exchange of a heavy $Z^{'}$ boson in models with heavy vector-like fermions and a scalar field, and a model with scalar leptoquarks. We provide predictions for the BSM couplings and expected mass values.

Primary author

Dr Dinesh Kumar (National Centre for Nuclear Research, Warsaw)


Enrico Maria Sessolo (NCBJ, Warsaw) Dr Kamila Kowalska (National Centre for Nuclear Research, Warsaw, Poland)

Presentation materials