Sensitivity projections for a dual-phase argon TPC optimized for light dark matter searches through the ionization channel

Understand

Dark matter lighter than 10 GeV/c$^2$ encompasses a promising range of candidates.

• A conceptual design for a new detector, DarkSide-LowMass, is presented, based on the DarkSide-50 detector and progress toward DarkSide-20k, optimized for a low-threshold electron-counting measurement.
• Sensitivity to light dark matter is explored for various potential energy thresholds and background rates.
• These studies show that DarkSide-LowMass can achieve sensitivity to light dark matter down to the solar neutrino floor for GeV-scale masses and significant sensitivity down to 10 MeV/c$^2$ considering the Migdal effect or interactions with electrons.