Implications for new physics in b→ s μ μ transitions after recent measurements by Belle and LHCb

We present a Bayesian analysis of the implications for new physics in semileptonic b→ s b→s transitions after including new measurements of RK RK at LHCb and new determinations of RK^* 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.