Inelastic dark matter scattering off Thallium cannot save DAMA

TL;DR

This study investigates whether inelastic dark matter scattering off Thallium in DAMA can explain the observed modulation signal, but finds it incompatible with null results from other experiments like XENON1T and CRESST-II.

Contribution

The paper provides a comprehensive analysis of inelastic DM-Thallium scattering, including uncertainties, and demonstrates it cannot account for DAMA's modulation signal given current experimental constraints.

Findings

Inelastic DM-Tl scattering regions are excluded by other direct detection constraints.

Uncertainties in Thallium quenching factor do not reconcile DAMA with null results.

Inelastic DM scattering off Thallium cannot explain DAMA's modulation signal.

Abstract

We study the compatibility of the observed DAMA modulation signal with inelastic scattering of dark matter (DM) off of the $0.1\%$ Thallium (Tl) dopant in DAMA. In this work we test whether there exist regions of parameter space where the Tl interpretation gives a good fit to the most recent data from DAMA, and whether these regions are compatible with the latest constraints from other direct detection experiments. Previously, Chang et al. in 2010, had proposed the Tl interpretation of the DAMA data, and more recently (in 2019) the DAMA/LIBRA collaboration found regions in parameter space of Tl inelastic scattering that differ by more than $10\sigma$ from a no modulation hypothesis. We have expanded upon their work by testing whether the regions of parameter space where inelastic DM-Tl scattering gives a good fit to the most recent DAMA data survive the constraints placed by the lack of a DM signal in XENON1T and CRESST-II. In addition, we have tested how these regions change with the main sources of uncertainty: the Tl quenching factor, which has never been measured directly, and the astrophysical uncertainties in the DM distribution. We conclude that inelastic DM scattering off Tl cannot explain the DAMA data in light of null results from other experiments.