Flavour with a Light Dynamical "Higgs Particle"

TL;DR

This paper investigates the flavor structure of Higgs-fermion interactions in models with strong dynamics behind a light Higgs, analyzing effective operators and deriving bounds from low-energy flavor experiments.

Contribution

It systematically studies flavor-changing Higgs couplings within the Minimal Flavour Violation framework, including loop corrections and CP-odd operators, providing new constraints on new physics effects.

Findings

Bounds on flavor-changing Higgs interactions from low-energy data

CP-odd operator coefficients are weakly constrained

Implications for experimental searches of flavor-changing Higgs processes

Abstract

The Higgs-fermion couplings are sensitive probes of possible new physics behind a stable light Higgs particle. It is then essential to identify the flavour pattern of those interactions. We consider the case in which a strong dynamics lies behind a light Higgs, and explore the implications within the Minimal Flavour Violation ansatz. The dominant effects on flavour-changing Higgs-fermion couplings stem in this context from operators with mass dimension <6, and we analyze all relevant chiral operators up to that order, including loop-corrections induced by 4-dimensional ones. Bounds on the operator coefficients are derived from a plethora of low-energy flavour transitions, providing a guideline on which flavour-changing Higgs interactions may be open to experimental scrutiny. In particular, the coefficient of a genuinely CP-odd operator is only softly constrained and therefore its impact is potentially interesting.