May 2022 Talks

This month I have two scheduled talks,

In the recent years, a series of measurements in the observables \(R_{K^{(*)}}\) and \(R_{D^{(*)}}\) concerning the semileptonic decays of the (B) mesons have shown hints of violations of Lepton Flavour Universality (LFU). An updated model-independent analysis of New Physics violating LFU, by using the Standard Model Effective Field Theory (SMEFT) Lagrangian with semileptonic dimension six operators at \(\Lambda = 1\,\mathrm{TeV}\) is presented. We perform a global fit, in order to assess the impact of the New Physics in a broad range of observables including \(B\)-physics, electroweak precision test, Higgs physics and nuclear \(\beta\) decays. We discuss the relevance of the mixing in the first generation for the observables with heavier lepton flavours. We use for the first time in this context a Montecarlo analysis of the likelihood function to extract the confidence intervals and correlations between observables. Our results show that a suitable strategy is to use a Gradient Boosting predictor as a proxy of the real likelihood function, and to analyze the SHAP values as a measure of the impact of each parameter of SMEFT Lagrangian in the fit.

The slides will be available at my repo, in their corresponding branch.