Linear flavour violation and anomalies in B physics

TL;DR

This paper introduces renormalizable new physics models with linear flavour violation that explain B-meson decay anomalies while maintaining consistency with flavour data and avoiding baryon- and lepton-number violations.

Contribution

It presents a novel class of models where new physics couples linearly to Standard Model fermions, providing a unified explanation for B-physics anomalies and flavour violation patterns.

Findings

Models fit B-meson decay anomalies effectively

Accidental symmetries suppress unwanted processes

Flavour-breaking couplings align with SM Yukawas

Abstract

We propose renormalizable models of new physics that can explain various anomalies observed in decays of B-mesons to electron and muon pairs. The new physics states couple to linear combinations of Standard Model fermions, yielding a pattern of flavour violation that gives a consistent fit to the gamut of flavour data. Accidental symmetries prevent contributions to baryon- and lepton-number-violating processes, as well as enforcing a loop suppression of new physics contributions to flavour violating processes. Data require that the new flavour-breaking couplings are largely aligned with the Yukawa couplings of the SM and so we also explore patterns of flavour symmetry breaking giving rise to this structure.