1. Liquid xenon scintillation measurements and pulse shape discrimination in the LUX dark matter detector
- Author
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Akerib, DS, Alsum, S, Araújo, HM, Bai, X, Bailey, AJ, Balajthy, J, Beltrame, P, Bernard, EP, Bernstein, A, Biesiadzinski, TP, Boulton, EM, Brás, P, Byram, D, Carmona-Benitez, MC, Chan, C, Currie, A, Cutter, JE, Davison, TJR, Dobi, A, Druszkiewicz, E, Edwards, BN, Fallon, SR, Fan, A, Fiorucci, S, Gaitskell, RJ, Genovesi, J, Ghag, C, Gilchriese, MGD, Hall, CR, Haselschwardt, SJ, Hertel, SA, Hogan, DP, Horn, M, Huang, DQ, Ignarra, CM, Jacobsen, RG, Ji, W, Kamdin, K, Kazkaz, K, Khaitan, D, Knoche, R, Lenardo, BG, Lesko, KT, Liao, J, Lindote, A, Lopes, MI, Manalaysay, A, Mannino, RL, Marzioni, MF, McKinsey, DN, Mei, DM, Mock, J, Moongweluwan, M, Morad, JA, Murphy, ASJ, Nehrkorn, C, Nelson, HN, Neves, F, O'Sullivan, K, Oliver-Mallory, KC, Palladino, KJ, Pease, EK, Rhyne, C, Shaw, S, Shutt, TA, Silva, C, Solmaz, M, Solovov, VN, Sorensen, P, Sumner, TJ, Szydagis, M, Taylor, DJ, Taylor, WC, Tennyson, BP, Terman, PA, Tiedt, DR, To, WH, Tripathi, M, Tvrznikova, L, Utku, U, Uvarov, S, Velan, V, Verbus, JR, Webb, RC, White, JT, Whitis, TJ, Witherell, MS, Wolfs, FLH, Xu, J, Yazdani, K, Young, SK, and Zhang, C
- Subjects
physics.ins-det - Abstract
Weakly interacting massive particles (WIMPs) are a leading candidate for dark matter and are expected to produce nuclear recoil (NR) events within liquid xenon time-projection chambers. We present a measurement of the scintillation timing characteristics of liquid xenon in the LUX dark matter detector and develop a pulse shape discriminant to be used for particle identification. To accurately measure the timing characteristics, we develop a template-fitting method to reconstruct the detection times of photons. Analyzing calibration data collected during the 2013-2016 LUX WIMP search, we provide a new measurement of the singlet-to-triplet scintillation ratio for electron recoils (ER) below 46 keV, and we make, to our knowledge, a first-ever measurement of the NR singlet-to-triplet ratio at recoil energies below 74 keV. We exploit the difference of the photon time spectra for NR and ER events by using a prompt fraction discrimination parameter, which is optimized using calibration data to have the least number of ER events that occur in a 50% NR acceptance region. We then demonstrate how this discriminant can be used in conjunction with the charge-to-light discrimination to possibly improve the signal-to-noise ratio for nuclear recoils.
- Published
- 2018