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

## TL;DR

This paper conducts a Bayesian global analysis of recent $b o s \mu\mu$ transition measurements, evaluating implications for new physics models including $Z'$ bosons and leptoquarks, and compares model probabilities.

## Contribution

It introduces a comprehensive Bayesian framework for analyzing $b o s \\mu\\mu$ anomalies and assesses various BSM models against recent experimental data.

## Key findings

- Bayesian credible regions for Wilson coefficients are established.
- Model comparisons favor certain BSM scenarios over others.
- Predictions for new physics couplings and masses are provided.

## Abstract

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.