Halo Independent Direct Detection of Momentum-Dependent Dark Matter

TL;DR

This paper demonstrates that the momentum dependence of dark matter interactions can be tested in direct detection experiments without knowing the dark matter velocity distribution, enabling new insights into dark matter microphysics.

Contribution

It introduces a method to probe momentum-dependent dark matter interactions independently of velocity distribution assumptions, especially for long-range interactions mediated by light particles.

Findings

Mediator mass constrained to $ extless 10$ MeV for certain dark matter masses.

Momentum dependence can be identified with multiple experiments and different targets.

Method applicable to long-range interactions from light mediators.

Abstract

We show that the momentum dependence of dark matter interactions with nuclei can be probed in direct detection experiments without knowledge of the dark matter velocity distribution. This is one of the few properties of DM microphysics that can be determined with direct detection alone, given a signal of dark matter in multiple direct detection experiments with different targets. Long-range interactions arising from the exchange of a light mediator are one example of momentum-dependent DM. For data produced from the exchange of a massless mediator we find for example that the mediator mass can be constrained to be $\lesssim 10$ MeV for DM in the 20-1000 GeV range in a halo-independent manner.