Higgsino-like Dark Matter From Sneutrino Late Decays

TL;DR

This paper proposes a novel non-thermal mechanism for generating Higgsino-like dark matter in the MSSM through late sneutrino decays, involving thermal freeze-in production and low-temperature decays.

Contribution

It introduces a new non-thermal production method for Higgsino-like DM via sneutrino late decays in the MSSM with right-handed neutrinos.

Findings

Sneutrino decays occur at temperatures much lower than freeze-out.

Higgsino-like DM relic density can be achieved through thermal freeze-in production.

Decays involve a mostly right-handed sneutrino with small Yukawa interactions.

Abstract

We consider Higgsino-like dark matter (DM) in the Minimal Supersymmetric Standard Model (MSSM) with additional right-handed neutrino chiral superfields, and propose a new non-thermal way of generating the right amount of relic DM via sneutrino late decays. Due to the large DM annihilation cross-section, decays must occur at lower temperatures than the freeze-out temperature $T_d\ll T_{F,\tilde{\chi}^0_1}\sim \mu/25$, implying a mostly right-handed lightest sneutrino with very small Yukawa interactions. In that context, the right amount of Higgsino-like DM relic density can be accounted for if sneutrinos are produced via thermal freeze-in in the early Universe.