The Scale Invariant Scotogenic Model: Dark Matter and the Scalar Sector

TL;DR

This paper explores how the scale invariant scotogenic model links dark matter properties with the scalar sector, highlighting new annihilation channels and experimental constraints within a neutrino mass framework.

Contribution

It introduces a scale invariant extension of the scotogenic model, analyzing dark matter interactions and scalar sector implications with novel annihilation processes and reduced Yukawa couplings.

Findings

Dark matter can annihilate via Higgs/dilaton mediated channels.

Small Yukawa couplings avoid scalar mass degeneracy.

Direct detection constraints are significant due to tree-level quark couplings.

Abstract

In this paper, we investigate the mutual impact between the dark matter (DM) requirements and the scalar sector in the scale invariant (SI) scotogenic model. The model is motivated by the neutrino mass and DM within a classically SI framework. It is a SI generalization of the scotogenic model, where the standard model (SM) is extended by a real singlet, an inert scalar doublet and three Majorana singlet fermions, where the lightest one ($N_{1}$) could play the DM candidate role. In addition to the annihilation channels $N_{1}N_{1}\rightarrow\ell_{\alpha}\ell_{\beta},\nu_{\alpha}\bar{\nu}_{\beta}$, the DM can be annihilated via few s-channel processes into SM particles, that are mediated by the Higgs/dilaton. This allows the new Yukawa interactions, that are responsible for neutrino mass generation, to take small values and therefore avoid the mass degeneracy between the CP-even and CP-odd inert scalars unlike the case of the minimal scotogenic model. In contrast to many Majorana DM models, the DM in the SI-scotogenic model couples to the quarks at tree-level, and hence the constraint from the direct detection experiments is very important on the space parameter. The aim of this work is to investigate the correlation between the DM requirements and the scalar sector in this model.