Halo-independent tests of dark matter annual modulation signals

TL;DR

This paper develops new halo-independent lower bounds on dark matter detection signals' cross section and density, using annual modulation data, which are robust against assumptions about the dark matter velocity distribution.

Contribution

It introduces novel halo-independent bounds on dark matter parameters based on annual modulation signals, applicable to multi-target detectors and independent of velocity distribution assumptions.

Findings

Bounds applied to DAMA/LIBRA data show strong constraints.

Results challenge standard halo model predictions.

Bounds are valid for multi-target detectors.

Abstract

I derive new halo-independent lower bounds on the product of the dark matter-nucleon scattering cross section and the local dark matter density that are valid for annual modulations of dark matter direct detection signals. They are obtained by making use of halo-independent bounds based on an expansion of the rate on the Earth's velocity that were derived in previous works. In combination with astrophysical measurements of the local energy density, an observed annual modulation implies a lower bound on the cross section that is independent of the velocity distribution and that must be fulfilled by any particle physics model. In order to illustrate the power of the bounds we apply them to DAMA/LIBRA data and obtain quite strong results when compared to the standard halo model predictions. We also extend the bounds to the case of multi-target detectors.