Implications for new physics in $$b\rightarrow s \mu \mu $$ b→sμμ transitions after recent measurements by Belle and LHCb

Abstract

Abstract We present a Bayesian analysis of the implications for new physics in semileptonic $$b\rightarrow s$$ b→s transitions after including new measurements of $$R_K$$ RK at LHCb and new determinations of $$R_{K^*}$$ RK∗ and $$R_{K^{*+}}$$ RK∗+ 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 $$Z^{'}$$ 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.