Revisiting (s)neutrino dark matter in natural SUSY

TL;DR

This paper explores natural SUSY models with light right-handed neutrinos, analyzing neutrino and sneutrino dark matter candidates, their production mechanisms, and the conditions needed for relic density consistency.

Contribution

It evaluates SUSY corrections to neutrino decay rates and investigates thermal and non-thermal sneutrino dark matter production, proposing model extensions for enhanced annihilation.

Findings

SUSY corrections to neutrino decay are too small to relax NuStar bounds.

Non-thermal sneutrino can match relic density with parameter tuning.

Thermal sneutrino dark matter requires model extensions for sufficient annihilation.

Abstract

We study natural supersymmetric scenarios with light right-handed neutrino superfields, and consider the possibility of having either a neutrino or a sneutrino as a dark matter candidate. For the former, we evaluate the possibility of having SUSY corrections on the $\nu_4\to\nu_\ell\gamma$ decay rate, such that the NuStar bounds are relaxed. We find that corrections are too small. For sneutrino dark matter, we consider thermal and non-thermal production, taking into account freeze-out, freeze-in and super-WIMP mechanisms. For the non-thermal case, we find that the $\tilde\nu_R$ can reproduce the observed relic density by adjusting the R-sneutrino mass and Yukawa couplings. For the thermal case, we find the need to extend the model in order to enhance sneutrino annihilations, which we exemplify in a model with an extended gauge symmetry.