Composite Flavon-Higgs Models

TL;DR

This paper proposes a composite Higgs model based on the $SU(6)/Sp(6)$ coset, introducing a flavon field that explains flavor hierarchies and predicts testable signals at colliders, while addressing flavor-changing constraints.

Contribution

It introduces a novel composite Higgs model with a flavon field from the $SU(6)/Sp(6)$ coset, linking flavor symmetry breaking to Higgs physics and collider phenomenology.

Findings

A light flavon below TeV scale can generate flavor hierarchies.

The model predicts flavor-changing neutral currents constrained by precision tests.

Potential signals at HL-LHC and future colliders for additional scalars.

Abstract

We consider a composite Higgs model based on the $SU(6)/Sp(6)$ coset, where an $U(1)$ subgroup of $Sp(6)$ is identified as the flavor symmetry. A complex scalar field $s$, which is a pseudo-Nambu-Goldstone boson of the broken symmetry, carries a flavor charge and plays the role of a flavon field. The $U(1)_F$ flavor symmetry is then broken by a VEV of the flavon field, which leads to a small parameter and generates the mass hierarchy between the top and bottom quarks. A light flavon below the TeV scale can be naturally introduced, which provides a fully testable model for the origin of flavor hierarchy. A light flavon also leads to substantial flavor changing neutral currents, which are strongly constrained by the flavor precision tests. The direct search of additional scalar bosons can also be conducted in HL-LHC and future hadron colliders.