Dark Matter from Freeze-In via the Neutrino Portal

Understand

We investigate a minimal neutrino portal dark matter (DM) model where a right-handed neutrino both generates the observed neutrino masses and mediates between the SM and the dark sector, which consists of a fermion and a boson.

• In contrast to earlier work, we explore regions of the parameter space where DM is produced via freeze-in instead of freeze-out motivated by the small neutrino Yukawa couplings in case of $\mathcal{O} \left( \mathrm{TeV} \right)$ heavy neutrinos.
• \\ For a non-resonant production of DM, its energy density is independent of the DM mass.
• Assuming a democratic coupling structure we find $M_N \approx 10 \, \mathrm{TeV}$.