Speaker
Description
We present the latest results of the low mass dark matter searches with the DarkSide-50 experiment. DarkSide-50 is a dual phase Time Projection Chamber based on low radioactivity argon. The full (12202 ± 180) kg * day dataset collected from 2015 to 2018 underground at the Laboratori Nazionali del Gran Sasso has been recently analyzed. In addition to the usual frequentist analysis, a Bayesian approach analysis has also been developed. This technique consolidates the frequentist exclusion constraints and allows a comprehensive treatment of the detector response model. The upper bounds on the spin independent WIMP-nucleon cross section show that DarkSide-50 establishes the most stringent constraints in the [1.2, 3.6] GeV/c^2 mass region. The inclusion of the so-called Migdal effect extends the excluded region down to a mass of 40 MeV/c^2. In addition, we exclude new parameter space for the dark matter-electron cross section, the axioelectric coupling constant, and the dark photon kinetic mixing parameter, and we produce the first dark matter direct-detection constraints on the mixing angle |Ue4|^2 for keV sterile neutrinos. We discuss how this increase in sensitivity, compared to the previous analysis published in 2018, is due to the adoption of a larger dataset, a more accurate background model, and a refined calibration. Finally, we present the status and the physics reach of the DarkSide-20k experiment, currently under construction at LNGS.
