Dark matter candidate in an extended type III seesaw scenario

TL;DR

This paper extends the type III seesaw model by adding a third triplet and a sterile neutrino, introducing a fermionic dark matter candidate consistent with experimental constraints.

Contribution

It proposes a novel extension of the type III seesaw model with a conserved  symmetry, leading to a viable fermionic dark matter candidate.

Findings

Identifies parameter space compatible with relic density and direct detection constraints.

Allows a wide range of dark matter masses within the extended model.

Demonstrates the model's consistency with current experimental bounds.

Abstract

The type III seesaw mechanism for neutrino mass generation usually makes use of at least two $Y = 0$, $SU(2)_L$ lepton triplets. We augment such a model with a third triplet and a sterile neutrino, both of which are odd under a conserved $\Z_2$ symmetry. With all new physics confined to the $\Z_2$-odd sector, whose low energy manifestation is in some higher-dimensional operators, a fermionic dark matter candidate is found to emerge. We identify the region of the parameter space of the scenario, which is consistent with all constraints from relic density and direct searches, and allows a wide range of masses for the dark matter candidate.