The ScotoSinglet Model: A Scalar Singlet Extension of the Scotogenic Model

TL;DR

This paper introduces the ScotoSinglet Model, extending the Scotogenic Model with a scalar singlet, which broadens the viable parameter space for scalar dark matter and alters neutrino mass generation mechanisms.

Contribution

The paper proposes a scalar singlet extension to the Scotogenic Model, significantly expanding the parameter space and modifying dark matter and neutrino mass phenomenology.

Findings

Scalar singlet broadens dark matter parameter space

Modified neutrino mass generation mechanisms

Enhanced compatibility with experimental constraints

Abstract

The Scotogenic Model is one of the most minimal models to account for both neutrino masses and dark matter (DM). In this model, neutrino masses are generated at the one-loop level, and in principle, both the lightest fermion singlet and the lightest neutral component of the scalar doublet can be viable DM candidates. However, the correct DM relic abundance can only be obtained in somewhat small regions of the parameter space, as there are strong constraints stemming from lepton flavour violation, neutrino masses, electroweak precision tests and direct detection. For the case of scalar DM, a sufficiently large lepton-number-violating coupling is required, whereas for fermionic DM, coannihilations are typically necessary. In this work, we study how the new scalar singlet modifies the phenomenology of the Scotogenic Model, particularly in the case of scalar DM. We find that the new singlet modifies both the phenomenology of neutrino masses and scalar DM, and opens up a large portion of the parameter space of the original model.