Detection Prospects for Majorana Fermion WIMPless Dark Matter

TL;DR

This paper investigates the detection prospects of Majorana fermion WIMPless dark matter through spin-dependent and spin-independent nuclear scattering, highlighting unique detection possibilities at IceCube/DeepCore.

Contribution

It introduces new models where Majorana fermion WIMPless dark matter can be detected via SD scattering despite being undetectable through SI scattering.

Findings

SD scattering can be detected at IceCube/DeepCore for certain models.

SI scattering is suppressed or absent in some models.

Detection strategies vary significantly with model parameters.

Abstract

We consider both velocity-dependent and velocity-independent contributions to spin-dependent (SD) and spin-independent (SI) nuclear scattering (including one-loop corrections) of WIMPless dark matter, in the case where the dark matter candidate is a Majorana fermion. We find that spin-independent scattering arises only from the mixing of exotic squarks, or from velocity-dependent terms. Nevertheless (and contrary to the case of MSSM neutralino WIMPs), we find a class of models which cannot be detected through SI scattering, but can be detected at IceCube/DeepCore through SD scattering. We study the detection prospects for both SI and SD detection strategies for a large range of Majorana fermion WIMPless model parameters.