Constraints on Sub-GeV Dark-Matter-Electron Scattering from the DarkSide-50 Experiment

• Published in: Physical review letters 2018-09, Vol.121 (11), p.111303-111303, Article 111303
• Main Authors: Agnes, P, Albuquerque, I F M, Alexander, T, Alton, A K, Araujo, G R, Asner, D M, Ave, M, Back, H O, Baldin, B, Batignani, G, Biery, K, Bocci, V, Bonfini, G, Bonivento, W, Bottino, B, Budano, F, Bussino, S, Cadeddu, M, Cadoni, M, Calaprice, F, Caminata, A, Canci, N, Candela, A, Caravati, M, Cariello, M, Carlini, M, Carpinelli, M, Catalanotti, S, Cataudella, V, Cavalcante, P, Cavuoti, S, Cereseto, R, Chepurnov, A, Cicalò, C, Cifarelli, L, Cocco, A G, Covone, G, D'Angelo, D, D'Incecco, M, D'Urso, D, Davini, S, De Candia, A, De Cecco, S, De Deo, M, De Filippis, G, De Rosa, G, De Vincenzi, M, Demontis, P, Derbin, A V, Devoto, A, Di Eusanio, F, Di Pietro, G, Dionisi, C, Downing, M, Edkins, E, Empl, A, Fan, A, Fiorillo, G, Fomenko, K, Franco, D, Gabriele, F, Gabrieli, A, Galbiati, C, Garcia Abia, P, Ghiano, C, Giagu, S, Giganti, C, Giovanetti, G K, Gorchakov, O, Goretti, A M, Granato, F, Gromov, M, Guan, M, Guardincerri, Y, Gulino, M, Hackett, B R, Hassanshahi, M H, Herner, K, Hosseini, B, Hughes, D, Humble, P, Hungerford, E V, Ianni, Al, Ianni, An, Ippolito, V, James, I, Johnson, T N, Kahn, Y, Keeter, K, Kendziora, C L, Kochanek, I, Koh, G, Korablev, D, Korga, G, Kubankin, A, Kuss, M, La Commara, M, Lai, M, Li, X, Lisanti, M
• Format: Article
• Language: English
• Subjects: Argon; ASTRONOMY AND ASTROPHYSICS; Astrophysics; Dark matter; Electroluminescence; Electrons; Particle physics; Physics; Radiation counters; Recoil; Scattering
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.121.111303

We present new constraints on sub-GeV dark-matter particles scattering off electrons based on 6780.0 kg d of data collected with the DarkSide-50 dual-phase argon time projection chamber. This analysis uses electroluminescence signals due to ionized electrons extracted from the liquid argon target. The detector has a very high trigger probability for these signals, allowing for an analysis threshold of three extracted electrons, or approximately 0.05 keVee. We calculate the expected recoil spectra for dark matter-electron scattering in argon and, under the assumption of momentum-independent scattering, improve upon existing limits from XENON10 for dark-matter particles with masses between 30 and 100  MeV/c^{2}.