Electroweak symmetry breaking and collider signatures in the next-to-minimal composite Higgs model

TL;DR

This paper analyzes a composite Higgs model with an extra scalar, identifying parameter regions consistent with current experiments and highlighting potential collider and indirect detection signals.

Contribution

It provides a detailed numerical analysis of the next-to-minimal composite Higgs model with a singlet scalar, exploring experimental constraints and phenomenological prospects.

Findings

Extra scalar below 1 TeV is unconstrained by current LHC data.

Parameter space compatible with electroweak symmetry breaking and flavor physics.

Potential signals in rare B decays, CP violation, and neutron EDM.

Abstract

We conduct a detailed numerical analysis of the composite pseudo-Nambu-Goldstone Higgs model based on the next-to-minimal coset $\text{SO}(6)/\text{SO}(5)\cong\text{SU}(4)/\text{Sp}(4)$, featuring an additional SM singlet scalar in the spectrum, which we allow to mix with the Higgs boson. We identify regions in parameter space compatible with all current experimental constraints, including radiative electroweak symmetry breaking, flavour physics, and direct searches at colliders. We find the additional scalar, with a mass predicted to be below a TeV, to be virtually unconstrained by current LHC data, but potentially in reach of run 2 searches. Promising indirect searches include rare semi-leptonic $B$ decays, CP violation in $B_s$ mixing, and the electric dipole moment of the neutron.