2018/02/28 by The DarkSide Collaboration, P. Agnes, I. F. M. Albuquerque +192 · 2 citations
Physics and Astronomy · #astro-ph.HE #astro-ph.CO
paper · pdf · doi:10.1103/physrevlett.121.081307
published as Phys. Rev. Lett. 121, 081307 (2018) · 9 pages, 8 figures; submission accepted by journal
arxiv created 2018/08/28 · arxiv updated 2018/08/29
We present the results of a search for dark matter WIMPs in the mass range below 20 GeV/c2 using a target of low-radioactivity argon. The data were obtained using the DarkSide-50 apparatus at Laboratori Nazionali del Gran Sasso (LNGS). The analysis is based on the ionization signal, for which the DarkSide-50 time projection chamber is fully efficient at 0.1 keVee. The observed rate in the detector at 0.5 keVee is about 1.5 events/keVee/kg/day and is almost entirely accounted for by known background sources. We obtain a 90% C.L. exclusion limit above 1.8 GeV/c2 for the spin-independent cross section of dark matter WIMPs on nucleons, extending the exclusion region for dark matter below previous limits in the range 1.8-6 GeV/c2.