The Higgs boson from an extended symmetry

TL;DR

This paper introduces a minimal composite Higgs model based on SO(5) symmetry, analyzing its phenomenology, constraints, and relation to other models like little Higgs and holographic theories.

Contribution

It provides a simple, explicit description of a composite Higgs scenario with SO(5) symmetry, including detailed phenomenological analysis and comparison to related models.

Findings

The model faces challenges in satisfying experimental constraints.

Extended gauge sectors have minimal impact on phenomenology.

Relations to little Higgs and holographic models are discussed.

Abstract

The variety of ideas put forward in the context of a "composite" picture for the Higgs boson calls for a simple and effective description of the related phenomenology. Such a description is given here by means of a "minimal" model and is explicitly applied to the example of a Higgs-top sector from an SO(5) symmetry. We discuss the spectrum, the ElectroWeak Precision Tests, B-physics and naturalness. We show the difficulty to comply with the different constraints. The extended gauge sector relative to the standard SU(2)xU(1), if there is any, has little or no impact on these considerations. We also discuss the relation of the "minimal" model with its "little Higgs" or "holographic" extensions based on the same symmetry.