Search for Dark Matter Particle Interactions with Electron Final States with DarkSide-50
P. Agnes, I. F. M. Albuquerque, T. Alexander, A. K. Alton, M. Ave, G. Batignani, G. Batignani, K. Biery, V. Bocci, W. Bonivento, B. Bottino, S. Bussino, M. Cadeddu, Mariano Cadoni, F. Calaprice, A. Caminata, M. de Campos, N. Canci, M. Caravati, N. Cargioli, M. Cariello, M. Carlini, V. Cataudella, P. Cavalcante, S. Cavuoti, S. Chashin, A. Chepurnov, C. Cicalò, G. Covone, D. D’Angelo, S. Davini, A. De Candia, S. De Cecco, G. De Filippis, G. De Rosa, A. Derbin, A. Devoto, M. D’Incecco, C. Dionisi, F. Dordei, M. Downing, D. D’Urso, G. Fiorillo, D. Franco, F. Gabriele, C. Galbiati, C. Ghiano, C. Giganti, G. K. Giovanetti, A. M. Goretti, Giovanni Grilli di Cortona, A. Grobov, M. Gromov, M. Guan, M. Gulino, B. R. Hackett, K. Herner, T. Hessel, B. Hosseini, F. Hubaut, E. Hungerford, An. Ianni, V. Ippolito, K. Keeter, C. Kendziora, Masato Kimura, I. Kochanek, D. Korablëv, G. Korga, A. Kubankin, M. Kuss, M. La Commara, M. Laí, X. Li, M. Lissia, G. Longo, O. Lychagina, I. N. Machulin, L. P. Mapelli, S. M. Mari, J. Maricic, A. Messina, R. Milincic, J. Monroe, M. Morrocchi, X. Mougeot, V. Muratova, P. Musico, A. Nozdrina, A. Oleinik, F. Ortica, L. Pagani, M. Pallavicini, L. Pandola, E. Pantic, E. Paoloni, K. Pelczar, N. Pelliccia, Stefano Piacentini, A. Pocar
Abstract
We present a search for dark matter particles with sub-$\mathrm{GeV}/{c}^{2}$ masses whose interactions have final state electrons using the DarkSide-50 experiment's $(12\text{ }306\ifmmode\pm\else\textpm\fi{}184)\text{ }\text{ }\mathrm{kg}\text{ }\mathrm{d}$ low-radioactivity liquid argon exposure. By analyzing the ionization signals, we exclude new parameter space for the dark matter-electron cross section ${\overline{\ensuremath{\sigma}}}_{e}$, the axioelectric coupling constant ${g}_{\mathrm{A}e}$, and the dark photon kinetic mixing parameter $\ensuremath{\kappa}$. We also set the first dark matter direct-detection constraints on the mixing angle ${|{U}_{e4}|}^{2}$ for $\mathrm{keV}/{c}^{2}$ sterile neutrinos.