Liquid xenon scintillation measurements and pulse shape discrimination in the LUX dark matter detector
Creators: name: The LUX Collaboration
name: Akerib, D. S.
name: Alsum, S.
name: Araújo, H. M.
name: Bai, X.
name: Bailey, A. J.
name: Balajthy, J.
name: Beltrame, P.
name: Bernard, E. P.
name: Bernstein, A.
name: Biesiadzinski, T. P.
name: Boulton, E. M.
name: Brás, P.
name: Byram, D.
name: Carmona-Benitez, M. C.
name: Chan, C.
name: Currie, A.
name: Cutter, J. E.
name: Davison, T. J. R.
name: Dobi, A.
name: Druszkiewicz, E.
name: Edwards, B. N.
name: Fallon, S. R.
name: Fan, A.
name: Fiorucci, S.
name: Gaitskell, R. J.
name: Genovesi, J.
name: Ghag, C.
name: Gilchriese, M. G. D.
name: Hall, C. R.
name: Haselschwardt, S. J.
name: Hertel, S. A.
name: Hogan, D. P.
name: Horn, M.
name: Huang, D. Q.
name: Ignarra, C. M.
name: Jacobsen, R. G.
name: Ji, W.
name: Kamdin, K.
name: Kazkaz, K.
name: Khaitan, D.
name: Knoche, R.
name: Lenardo, B. G.
name: Lesko, K. T.
name: Liao, J.
name: Lindote, A.
name: Lopes, M. I.
name: Manalaysay, A.
name: Mannino, R. L.
name: Marzioni, M. F.
name: McKinsey, D. N.
name: Mei, D. M.
name: Mock, J.
name: Moongweluwan, M.
name: Morad, J. A.
name: Murphy, A. St. J.
name: Nehrkorn, C.
name: Nelson, H. N.
name: Neves, F.
name: O'Sullivan, K.
name: Oliver-Mallory, K. C.
name: Palladino, K. J.
name: Pease, E. K.
name: Rhyne, C.
name: Shaw, S.
name: Shutt, T. A.
name: Silva, C.
name: Solmaz, M.
name: Solovov, V. N.
name: Sorensen, P.
name: Sumner, T. J.
name: Szydagis, M.
name: Taylor, D. J.
name: Taylor, W. C.
name: Tennyson, B. P.
name: Terman, P. A.
name: Tiedt, D. R.
name: To, W. H.
name: Tripathi, M.
name: Tvrznikova, L.
name: Utku, U.
name: Uvarov, S.
name: Velan, V.
name: Verbus, J. R.
name: Webb, R. C.
name: White, J. T.
name: Whitis, T. J.
name: Witherell, M. S.
name: Wolfs, F. L. H.
name: Xu, J.
name: Yazdani, K.
name: Young, S. K.
name: Zhang, C.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: 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 2013-16 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 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.
description: 16 pages, 11 figures