Brief on Dark Matter in the Type Ib Seesaw Model: a GeV-scale Dirac neutrino portal

TL;DR

This paper explores a minimal type Ib seesaw model linking neutrino mass generation to dark matter, proposing a fermionic dark matter candidate produced via freeze-in, and connecting it to laboratory experiments through neutrino mixing.

Contribution

It introduces a minimal dark matter extension to the type Ib seesaw model with a fermionic dark matter candidate and analyzes its relic abundance and experimental implications.

Findings

Dark matter can be produced via freeze-in in this model.

The model links neutrino physics to dark matter phenomenology.

Parameter space allows for correct relic abundance and testable predictions.

Abstract

The type Ib seesaw, as an alternative explanation to the origin of neutrino mass, provides a new intriguing way to connect the neutrino physics to cosmology. In this proceeding, we consider a minimal type Ib seesaw model where the effective neutrino mass operator involves two different Higgs doublets and a heavy Dirac mass. We propose a minimal dark matter extension of this model, in which the Dirac heavy neutrino is coupled to a dark Dirac fermion and a dark complex scalar field, both odd under a discrete $Z_2$ symmetry, where the lighter one serves as a dark matter candidate. Focussing on the fermionic dark matter case, we explore the parameter space of the seesaw Yukawa couplings, the neutrino portal couplings and dark scalar to dark fermion mass ratio, where correct dark matter relic abundance can be produced by the freeze-in mechanism. By considering the mixing between the standard model neutrinos and the heavy neutrino, a connection can be built between dark matter production and laboratory experiments.