Loop-Generated Neutrino Masses in Composite Higgs Models

TL;DR

This paper introduces a composite model for neutrino masses generated through loop processes involving $ ext{Z}_2$-odd scalars, which can also account for dark matter, within various composite Higgs frameworks.

Contribution

It proposes a novel composite scotogenic model for neutrino masses with multiple coupling approaches and explores dark matter candidates within this setup.

Findings

Neutrino masses generated via loops of $ ext{Z}_2$-odd scalars.

Model remains viable with right-handed neutrinos from TeV to Planck scale.

Lightest $ ext{Z}_2$-odd scalar can serve as dark matter.

Abstract

We present a composite scotogenic model for neutrino masses, which are generated via loops of $\mathbb{Z}_2$-odd composite scalars. We consider three different approaches to the couplings of the neutrinos (including three right-handed singlets) and the composite sector: ETC-like four-fermion interactions, fundamental partial compositeness and fermion partial compositeness. In all cases, the model can feature sizeable couplings and remain viable with respect to various experimental constraints if the three $ \mathbb{Z}_2 $-odd right-handed neutrinos have masses between the TeV and the Planck scales. Additionally, the lightest $\mathbb{Z}_2$-odd composite scalar may play the role of Dark Matter, either via thermal freeze-out or as an asymmetric relic. This mechanism can be featured in a variety of models based on vacuum misalignment. For concreteness, we demonstrate it in a composite two-Higgs scheme based on the coset SU(6)/Sp(6).