Quantifying Astrophysical Uncertainties on Dark Matter Direct Detection Results

TL;DR

This paper assesses how uncertainties in galactic dark matter distribution and velocity profiles affect the interpretation of direct detection experiments, finding that the impact is generally within an order of magnitude for high-mass dark matter.

Contribution

It provides a comprehensive analysis of astrophysical uncertainties impacting dark matter direct detection constraints, including non-Maxwellian velocities and dark disk effects.

Findings

Uncertainty in cross section constraints is less than an order of magnitude for >100 GeV dark matter.

Non-Maxwellian velocity distributions have limited impact on detection constraints.

Dark disk presence does not significantly alter the interpretation of experimental results.

Abstract

We attempt to estimate the uncertainty in the constraints on the spin independent dark matter-nucleon cross section due to our lack of knowledge of the dark matter phase space in the galaxy. We fit the density of dark matter before investigating the possible solutions of the Jeans equation compatible with those fits in order to understand what velocity dispersions we might expect at the solar radius. We take into account the possibility of non-Maxwellian velocity distributions and the possible presence of a dark disk. Combining all these effects, we still find that the uncertainty in the interpretation of direct detection experiments for high (>100 GeV) mass dark matter candidates is less than an order of magnitude in cross section.