Investigation of background electron emission in the LUX detector

Author(s): Akerib, DS; Alsum, S; Araujo, HM; Bai, X; Balajthy, J; Baxter, A; Bernard, EP; Bernstein, A; Biesiadzinski, TP; Boulton, EM; Boxer, B; Bras, P; Burdin, S; Byram, D; Carmona-Benitez, MC; Chan, C; Cutter, JE; Viveiros, L de; Druszkiewicz, E; Fan, A; Fiorucci, S; Gaitskell, RJ; Ghag, C; Gilchriese, MGD; Gwilliam, C; Hall, CR; Haselschwardt, SJ; Hertel, SA; Hogan, DP; Horn, M; Huang, DQ; Ignarra, CM; Jacobsen, RG; Jahangir, O; Ji, W; Kamdin, K; Kazkaz, K; Khaitan, D; Korolkova, EV; Kravitz, S; Kudryavtsev, VA; Leason, E; Lenardo, BG; Lesko, KT; Liao, J; Lin, J; Lindote, A; Lopes, MI; Manalaysay, A; Mannino, RL; Marangou, N; McKinsey, DN; Mei, DM; Moongweluwan, M; Morad, JA; Murphy, A St J; Naylor, A; Nehrkorn, C; Nelson, HN; Neves, F; Nilima, A; Oliver-Mallory, KC; Palladino, KJ; Pease, EK; Riffard, Q; Rischbieter, GRC; Rhyne, C; Rossiter, P; Shaw, S; Shutt, TA; Silva, C; Solmaz, M; Solovov, VN; Sorensen, P; Sumner, TJ; Szydagis, M; Taylor, DJ; Taylor, R; Taylor, WC; Tennyson, BP; Terman, PA; Tiedt, DR; To, WH; Tvrznikova, L; Utku, U | Abstract: Dual-phase xenon detectors, as currently used in direct detection dark matter experiments, have observed elevated rates of signals from electron emission processes in the low energy region. While this background negatively impacts detector performance in various ways, its origins have only been partially studied. In this paper, we report a systematic investigation of the electron pathologies observed in the LUX dark matter experiment. We characterize different electron populations based on their emission intensities and their correlations with preceding energy depositions in the detector. By studying these electron backgrounds under different experimental conditions, we identified the possible mechanisms that may contribute to the electron emission. We report the observed electron event rate in LUX after background rejection, and discuss how such backgrounds can be further mitigated in ongoing and future xenon-based dark matter experiments.