Seesaw neutrino determination of the dark matter relic density

In this article we show that in the usual type-I seesaw framework, augmented solely by a neutrino portal interaction, the dark matter (DM) relic density can be created through freeze-in, in a manner fully determined by the seesaw interactions and the DM particle mass. This simple freeze-in scenario, where dark matter is not in a seesaw state, proceeds through slow, seesaw-induced decays of Higgs W and Z bosons. We identify two scenarios, one of which predicts the existence of an observable neutrino line.

Automated summary

In this article, we demonstrate that the dark matter relic density can be produced through freeze-in within the usual type-I seesaw framework, augmented solely by a neutrino portal interaction. This simple freeze-in scenario, where dark matter is not in a seesaw state, involves slow, seesaw-induced decays of Higgs W and Z bosons. We identify two scenarios, with one predicting the existence of an observable neutrino line.