A More Natural Composite Higgs Model

TL;DR

This paper proposes a composite Higgs model based on the SU(6)/Sp(6) coset that reduces tuning issues by utilizing enhanced symmetries and collective symmetry breaking, predicting light extra Higgs bosons and testable deviations in couplings.

Contribution

It introduces a novel composite Higgs model with an SU(6)/Sp(6) coset that minimizes tuning and incorporates the little Higgs mechanism without new elementary fields.

Findings

Model predicts light additional Higgs bosons detectable at future LHC runs.

Deviations in Higgs and gauge boson couplings are close to current experimental limits.

The approach reduces the tuning problem in composite Higgs models.

Abstract

Composite Higgs models provide an attractive solution to the hierarchy problem. However, many realistic models suffer from tuning problems in the Higgs potential. There are often large contributions from the UV dynamics of the composite resonances to the Higgs potential, and tuning between the quadratic term and the quartic term is required to separate the electroweak breaking scale and the compositeness scale. We consider a composite Higgs model based on the $SU(6)/Sp(6)$ coset, where an enhanced symmetry on the fermion resonances can minimize the Higgs quadratic term. Moreover, a Higgs quartic term from the collective symmetry breaking of the little Higgs mechanism can be realized by the partial compositeness couplings between elementary Standard Model fermions and the composite operators, without introducing new elementary fields beyond the Standard Model and the composite sector. The model contains two Higgs doublets, as well as several additional pseudo-Nambu-Goldstone bosons. To avoid tuning, the extra Higgs bosons are expected to be relatively light and may be probed in the future LHC runs. The deviations of the Higgs couplings and the weak gauge boson couplings also provide important tests as they are expected to be close to the current limits in this model.