General Composite Higgs Models

TL;DR

This paper develops a broad class of composite Higgs models based on the SO(5)/SO(4) coset, introducing the Minimal Higgs Potential hypothesis and analyzing conditions for a 125 GeV Higgs with light resonances, while connecting to existing moose models.

Contribution

It constructs a general framework for composite Higgs models beyond moose-type, incorporating the MHP hypothesis and analyzing resonance properties for realistic Higgs mass.

Findings

Light fermion resonances are necessary for a 125 GeV Higgs.

Models can accommodate a heavy Higgs around 320 GeV.

Electroweak precision tests can be satisfied within these models.

Abstract

We construct a general class of pseudo-Goldstone composite Higgs models, within the minimal SO(5)/SO(4) coset structure, that are not necessarily of moose-type. We characterize the main properties these models should have in order to give rise to a Higgs mass around 125 GeV. We assume the existence of relatively light and weakly coupled spin 1 and 1/2 resonances. In absence of a symmetry principle, we introduce the Minimal Higgs Potential (MHP) hypothesis: the Higgs potential is assumed to be one-loop dominated by the SM fields and the above resonances, with a contribution that is made calculable by imposing suitable generalizations of the first and second Weinberg sum rules. We show that a 125 GeV Higgs requires light, often sub-TeV, fermion resonances. Their presence can also be important for the models to successfully pass the electroweak precision tests. Interestingly enough, the latter can also be passed by models with a heavy Higgs around 320 GeV. The composite Higgs models of the moose-type considered in the literature can be seen as particular limits of our class of models.