Extracting Halo Independent Information from Dark Matter Electron Scattering Data

TL;DR

This paper extends a formalism to analyze dark matter-electron scattering data, enabling extraction of astrophysics-independent information and testing data compatibility, with implications for future detector designs.

Contribution

It introduces a novel extension of the halo-independent formalism to dark-matter-electron interactions, allowing for astrophysics-independent analysis of experimental data.

Findings

Determining dark matter mass and velocity distribution is challenging with spectra populating few low-lying bins.

The formalism can test compatibility of existing data sets like SENSEI and EDELWEISS.

Predictions are made for future experiments such as GaAs-based detectors.

Abstract

Direct detection experiments and the interpretation of their results are sensitive to the velocity structure of the dark matter in our galactic halo. In this work, we extend the formalism that deals with such astrophysics-driven uncertainties, originally introduced in the context of dark-matter-nuclear scattering, to include dark-matter-electron scattering interactions. Using mock data, we demonstrate that the ability to determine the correct dark matter mass and velocity distribution is depleted for recoil spectra which only populate a few low-lying bins, such as models involving a light mediator. We also demonstrate how this formalism allows one to test the compatibility of existing experimental data sets (e.g. SENSEI and EDELWEISS), as well as make predictions for possible future experiments (e.g. GaAs-based detectors).