Dark Matter Detection with Polarized Detectors

TL;DR

This paper explores how polarized dark-matter detectors could distinguish between fermionic and scalar WIMP models by analyzing recoil distributions, highlighting the potential for polarization-dependent signals in fermionic cases.

Contribution

It proposes using nuclear polarization in detectors to differentiate dark-matter particle types based on their parity-violating interactions.

Findings

Recoil distributions depend on nuclear spin orientation for fermionic WIMPs.

Scalar WIMPs produce negligible polarization-dependent effects due to velocity suppression.

Large exposures are needed to observe polarization modulation effects.

Abstract

We consider the prospects to use polarized dark-matter detectors to discriminate between various dark-matter models. If WIMPs are fermions and participate in parity-violating interactions with ordinary matter, then the recoil-direction and recoil-energy distributions of nuclei in detectors will depend on the orientation of the initial nuclear spin with respect to the velocity of the detector through the Galactic halo. If, however, WIMPS are scalars, the only possible polarization-dependent interactions are extremely velocity-suppressed and, therefore, unobservable. Since the amplitude of this polarization modulation is fixed by the detector speed through the halo, in units of the speed of light, exposures several times larger than those of current experiments will be required to be probe this effect.