Fermionic WIMPs and Vacuum Stability in the Scotogenic Model

TL;DR

This paper shows that vacuum stability constraints significantly limit fermionic WIMP dark matter scenarios in the scotogenic model, with most parameter points failing due to destabilisation at high scales.

Contribution

It provides a detailed analysis of vacuum stability constraints on fermionic WIMP dark matter within the scotogenic model, highlighting the theoretical limitations.

Findings

Over 90% of viable parameter points are inconsistent due to vacuum destabilisation.

Sizable Yukawa couplings necessary for dark matter lead to vacuum instability.

Most parameter space compatible with experimental constraints is ruled out by stability issues.

Abstract

We demonstrate that the condition of vacuum stability severely restricts scenarios with fermionic WIMP dark matter in the scotogenic model. The sizable Yukawa couplings that are required to satisfy the dark matter constraint via thermal freeze-out in these scenarios tend to destabilise the vacuum at scales below that of the heaviest singlet fermion, rendering the model inconsistent from a theoretical point of view. By means of a scan over the parameter space, we study the impact of these renormalisation group effects on the viable regions of this model. Our analysis shows that a fraction of more than 90% of the points compatible with all known experimental constraints - including neutrino masses, the dark matter density, and lepton flavour violation - is actually inconsistent.