Ultra-Low Energy Calibration of LUX Detector using \(^{127}\)Xe Electron Capture

• Published in: arXiv.org 2017-09
• Main Authors: LUX Collaboration, Akerib, D S, Alsum, S, Araújo, H M, Bai, X, Bailey, A J, Balajthy, J, Beltrame, P, Bernard, E P, Bernstein, A, Biesiadzinski, T P, Boulton, E M, Brás, P, Byram, D, Cahn, S B, Carmona-Benitez, M C, Chan, C, Currie, A, Cutter, J E, Davison, T J R, Dobi, A, Druszkiewicz, E, Edwards, B N, Fallon, S R, Fan, A, Fiorucci, S, Gaitskell, R J, Genovesi, J, Ghag, C, Gilchriese, M G D, Hall, C R, Hanhardt, M, Haselschwardt, S J, Hertel, S A, Hogan, D P, Horn, M, Huang, D Q, Ignarra, C M, Jacobsen, R G, W Ji, Kamdin, K, Kazkaz, K, Khaitan, D, Knoche, R, Larsen, N A, Lenardo, B G, Lesko, K T, Lindote, A, Lopes, M I, Manalaysay, A, Mannino, R L, Marzioni, M F, McKinsey, D N, Mei, D M, Mock, J, Moongweluwan, M, Morad, J A, Murphy, A St J, Nehrkorn, C, Nelson, H N, Neves, F, O'Sullivan, K, Oliver-Mallory, K C, Palladino, K J, Pease, E K, Rhyne, C, Shaw, S, Shutt, T A, Silva, C, Solmaz, M, Solovov, V N, Sorensen, P, Sumner, T J, Szydagis, M, Taylor, D J, Taylor, W C, Tennyson, B P, Terman, P A, Tiedt, D R, To, W H, Tripathi, M, Tvrznikova, L, Uvarov, S, Velan, V, Verbus, J R, Webb, R C, White, J T, Whitis, T J, Witherell, M S, Wolfs, F L H, J Xu, Yazdani, K, Young, S K, Zhang, C
• Format: Article
• Language: English
• Subjects: Beta decay; Calibration; Cascades; Electric fields; Electron capture; Electrons; Gamma rays; Ionization; Recoil; Variation; Weakly interacting massive particles; Xenon
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1709.00800

We report an absolute calibration of the ionization yields(\(\textit{Q\)_y\(})\) and fluctuations for electronic recoil events in liquid xenon at discrete energies between 186 eV and 33.2 keV. The average electric field applied across the liquid xenon target is 180 V/cm. The data are obtained using low energy \(^{127}\)Xe electron capture decay events from the 95.0-day first run from LUX (WS2013) in search of Weakly Interacting Massive Particles (WIMPs). The sequence of gamma-ray and X-ray cascades associated with \(^{127}\)I de-excitations produces clearly identified 2-vertex events in the LUX detector. We observe the K- (binding energy, 33.2 keV), L- (5.2 keV), M- (1.1 keV), and N- (186 eV) shell cascade events and verify that the relative ratio of observed events for each shell agrees with calculations. The N-shell cascade analysis includes single extracted electron (SE) events and represents the lowest-energy electronic recoil \(\textit{in situ}\) measurements that have been explored in liquid xenon.