Direct Dark Matter Detection - A spin 3/2 WIMP candidate

TL;DR

This paper explores a spin 3/2 WIMP dark matter candidate with neutrino-like interactions, analyzing its viability, cross sections, and detection signatures, including potential negative annual modulation signals for heavy targets.

Contribution

It introduces a novel spin 3/2 dark matter candidate with detailed predictions for detection rates and unique modulation signatures, expanding the scope of WIMP models.

Findings

Majorana case can account for all dark matter within 70-160 GeV

Elementary spin-dependent cross section is 1.7 x 10^-2 pb

Heavy targets may show negative annual modulation

Abstract

We consider a Dark Matter candidate particle of spin 3/2 with neutrino-like Standard Model strength interactions. In the Majorana case, the particle can account for all of the Dark Matter for a range of masses between 70-160 GeV, depending on the strength of the Higgs couplings. The elementary spin-dependent cross section on the nucleon is calculated to be 1.7 x 10^-2 pb, and does not depend on the mass or any additional parameters. The Dirac case is excluded by the very large coherent cross section. The amplitude at the nuclear level is of the purely isovector form. We make detailed predictions for differential and total rates of scattering on a variety of nuclear targets of interest to the current direct detection experiments. For heavy targets the annual modulation amplitude is predicted to be negative, which may help to determine the mass of the WIMP if and when data become available.