Light dark matter search with DarkSide-50

TL;DR

This paper reports new limits on light dark matter particles using the DarkSide-50 detector, extending sensitivity to lower masses and exploring interactions with electrons, including effects like the Migdal effect.

Contribution

It provides the latest experimental constraints on light dark matter interactions in the 1.2 to 3.6 GeV/c^2 mass range, including the first limits considering the Migdal effect.

Findings

Improved limits on spin-independent WIMP-nucleon interactions for light masses.

Extended sensitivity down to 40 MeV/c^2 using the Migdal effect.

Set new constraints on dark matter-electron interactions.

Abstract

We present the latest results from the search for light dark matter particle interactions with the DarkSide-50 dual-phase liquid argon time projection chamber. This analysis, based on the ionization signal only, improves the existing limits for spin-independent WIMP-nucleon interactions in the $[1.2, 3.6]$ GeV/c$^2$ mass range. The sensitivity is extended down to 40 MeV/c$^2$ by assuming the Migdal effect, responsible for an additional ionization signal from the recoiling atom. Finally, we set new constraints to interactions of dark matter particles with electrons in the final state, namely WIMPs, galactic axions, dark photons, and sterile neutrinos.