Halo uncertainties in electron recoil events at direct detection experiments

TL;DR

This paper systematically studies how astrophysical uncertainties in dark matter halo models affect electron recoil detection rates, revealing significant deviations in experimental bounds.

Contribution

It provides a comprehensive analysis of the impact of astrophysical uncertainties on electron recoil signals in dark matter direct detection experiments.

Findings

Up to 50% deviation in exclusion bounds within the standard halo model.

Similar deviations observed with non-standard halo models fitted to cosmological simulations.

Larger deviations occur when considering observational uncertainties.

Abstract

The dark matter direct detection rates are highly correlated with the phase space distribution of dark matter particles in our galactic neighbourhood. In this paper, we make a systematic study of the impact of astrophysical uncertainties on electron recoil events at the direct detection experiments with Xenon and semiconductor detectors. We find that within the standard halo model there can be up to $ \sim 50\%$ deviation from the fiducial choice in the exclusion bounds from these observational uncertainties. For non-standard halo models, we report a similar deviation from the fiducial standard halo model when fitted with recent cosmological $N$-body simulations while even larger deviations are obtained in case of the observational uncertainties.