Flavor and CP Invariant Composite Higgs Models

TL;DR

This paper investigates flavor and CP symmetry protections in composite Higgs models, proposing mechanisms to reconcile flavor symmetry with experimental constraints and exploring implications for LHC signals and CP violation.

Contribution

It introduces novel symmetry-based protection mechanisms in composite Higgs models, enabling compatibility with precision tests and offering new collider signatures.

Findings

Flavor symmetric composite sectors can satisfy electroweak constraints

Light quarks can be substantially or fully composite, affecting LHC signals

New protection mechanisms reduce CP violation effects

Abstract

The flavor protection in composite Higgs models with partial compositeness is known to be insufficient. We explore the possibility to alleviate the tension with CP odd observables by assuming that flavor or CP are symmetries of the composite sector, broken by the coupling to Standard Model fields. One realization is that the composite sector has a flavor symmetry SU(3) or SU(3)_U x SU(3)_D which allows us to realize Minimal Flavor Violation. We show how to avoid the previously problematic tension between a flavor symmetric composite sector and electro-weak precision tests. Some of the light quarks are substantially or even fully composite with striking signals at the LHC. We discuss the constraints from recent dijet mass measurements and give an outlook on the discovery potential. We also present a different protection mechanism where we separate the generation of flavor hierarchies and the origin of CP violation. This can eliminate or safely reduce unwanted CP violating effects, realizing effectively "Minimal CP Violation" and is compatible with a dynamical generation of flavor at low scales.