Anomalies in B mesons decays: A phenomenological approach

TL;DR

This paper analyzes B meson decay anomalies using a model-independent effective Hamiltonian approach, identifying scenarios with multiple Wilson coefficient modifications that best explain deviations from the Standard Model, and discusses implications for leptoquark models.

Contribution

It introduces a comprehensive global fit analysis of Wilson coefficients considering multiple New Physics scenarios, highlighting the most favored configurations for explaining B-physics anomalies.

Findings

The scenario with three Wilson coefficients modified best explains the anomalies.

Restricted scenarios can achieve similar fits with fewer parameters.

Implications for leptoquark models are discussed.

Abstract

The experimental measurements on flavour physics, in tension with Standard Model predictions, exhibit large sources of Lepton Flavour Universality violation. We perform an analysis of the effects of the global fits on the Wilson coefficients assuming a model independent effective Hamiltonian approach, by including a set of different scenarios in which the New Physics contributions to the Wilson coefficients are present in one, two or three of the Wilson coefficients at a time. We compare the results of the global fit with respect to two cases: the Standard Model and the more general case in which New Physics modifies three independent Wilson coefficients. The last mentioned scenario is the favoured one for explaining the tension between Standard Model predictions and B-physics anomalies, but a specific more restricted scenario can provide similar goodness with a smaller set of free parameters. A discussion of the implications of our analysis in leptoquark models is included.