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Adhikari P, Ajaj R, Alpízar-Venegas M, Amaudruz PA, Auty DJ, Batygov M, Beltran B, Benmansour H, Bina CE, Bonatt J, Bonivento W, Boulay MG, Broerman B, Bueno JF, Burghardt PM, Butcher A, Cadeddu M, Cai B, Cárdenas-Montes M, Cavuoti S, Chen M, Chen Y, Cleveland BT, Corning JM, Cranshaw D, Daugherty S, DelGobbo P, Dering K, DiGioseffo J, Di Stefano P, Doria L, Duncan FA, Dunford M, Ellingwood E, Erlandson A, Farahani SS, Fatemighomi N, Fiorillo G, Florian S, Flower T, Ford RJ, Gagnon R, Gallacher D, García Abia P, Garg S, Giampa P, Goeldi D, Golovko V, Gorel P, Graham K, Grant DR, Grobov A, Hallin AL, Hamstra M, Harvey PJ, Hearns C, Hugues T, Ilyasov A, Joy A, Jigmeddorj B, Jillings CJ, Kamaev O, Kaur G, Kemp A, Kochanek I, Kuźniak M, Lai M, Langrock S, Lehnert B, Leonhardt A, Levashko N, Li X, Lidgard J, Lindner T, Lissia M, Lock J, Longo G, Machulin I, McDonald AB, McElroy T, McGinn T, McLaughlin JB, Mehdiyev R, Mielnichuk C, Monroe J, Nadeau P, Nantais C, Ng C, Noble AJ, O’Dwyer E, Oliviéro G, Ouellet C, Pal S, Pasuthip P, Peeters SJM, Perry M, Pesudo V, Picciau E, Piro MC, Pollmann TR, Rand ET, Rethmeier C, Retière F, Rodríguez-García I, Roszkowski L, Ruhland JB, Sánchez-García E, Santorelli R, Sinclair D, Skensved P, Smith B, Smith NJT, Sonley T, Soukup J, Stainforth R, Stone C, Strickland V, Stringer M, Sur B, Tang J, Vázquez-Jáuregui E, Viel S, Walding J, Waqar M, Ward M, Westerdale S, Willis J, Zuñiga-Reyes A. Pulse-shape discrimination against low-energy Ar-39 beta decays in liquid argon with 4.5 tonne-years of DEAP-3600 data. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2021; 81:823. [PMID: 34720726 PMCID: PMC8550104 DOI: 10.1140/epjc/s10052-021-09514-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 07/30/2021] [Indexed: 06/13/2023]
Abstract
The DEAP-3600 detector searches for the scintillation signal from dark matter particles scattering on a 3.3 tonne liquid argon target. The largest background comes from 39 Ar beta decays and is suppressed using pulse-shape discrimination (PSD). We use two types of PSD estimator: the prompt-fraction, which considers the fraction of the scintillation signal in a narrow and a wide time window around the event peak, and the log-likelihood-ratio, which compares the observed photon arrival times to a signal and a background model. We furthermore use two algorithms to determine the number of photons detected at a given time: (1) simply dividing the charge of each PMT pulse by the mean single-photoelectron charge, and (2) a likelihood analysis that considers the probability to detect a certain number of photons at a given time, based on a model for the scintillation pulse shape and for afterpulsing in the light detectors. The prompt-fraction performs approximately as well as the log-likelihood-ratio PSD algorithm if the photon detection times are not biased by detector effects. We explain this result using a model for the information carried by scintillation photons as a function of the time when they are detected.
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Affiliation(s)
- P. Adhikari
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
| | - R. Ajaj
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
- Arthur B. McDonald Canadian Astroparticle Physics Research Institute, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - M. Alpízar-Venegas
- Instituto de Física, Universidad Nacional Autónoma de México, A. P. 20-364, 01000 Mexico, D.F. Mexico
| | | | - D. J. Auty
- Department of Physics, University of Alberta, Edmonton, AB T6G 2R3 Canada
- Arthur B. McDonald Canadian Astroparticle Physics Research Institute, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - M. Batygov
- Department of Physics and Astronomy, Laurentian University, Sudbury, ON P3E 2C6 Canada
| | - B. Beltran
- Department of Physics, University of Alberta, Edmonton, AB T6G 2R3 Canada
| | - H. Benmansour
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - C. E. Bina
- Department of Physics, University of Alberta, Edmonton, AB T6G 2R3 Canada
- Arthur B. McDonald Canadian Astroparticle Physics Research Institute, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - J. Bonatt
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 Canada
| | | | - M. G. Boulay
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
| | - B. Broerman
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - J. F. Bueno
- Department of Physics, University of Alberta, Edmonton, AB T6G 2R3 Canada
| | - P. M. Burghardt
- Department of Physics, Technische Universität München, 80333 Munich, Germany
| | - A. Butcher
- Royal Holloway University London, Egham Hill, Egham, Surrey TW20 0EX UK
| | | | - B. Cai
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
- Arthur B. McDonald Canadian Astroparticle Physics Research Institute, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - M. Cárdenas-Montes
- Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, 28040 Madrid, Spain
| | - S. Cavuoti
- Physics Department, Università degli Studi “Federico II” di Napoli, 80126 Naples, Italy
- INFN Napoli, 80126 Naples, Italy
- INAF-Astronomical Observatory of Capodimonte, Salita Moiariello 16, 80131 Naples, Italy
| | - M. Chen
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - Y. Chen
- Department of Physics, University of Alberta, Edmonton, AB T6G 2R3 Canada
| | - B. T. Cleveland
- Department of Physics and Astronomy, Laurentian University, Sudbury, ON P3E 2C6 Canada
- SNOLAB, Lively, ON P3Y 1M3 Canada
| | - J. M. Corning
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - D. Cranshaw
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - S. Daugherty
- Department of Physics and Astronomy, Laurentian University, Sudbury, ON P3E 2C6 Canada
| | - P. DelGobbo
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
- Arthur B. McDonald Canadian Astroparticle Physics Research Institute, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - K. Dering
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - J. DiGioseffo
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
| | - P. Di Stefano
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - L. Doria
- PRISMA+ Cluster of Excellence and Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, 55128 Mainz, Germany
| | | | - M. Dunford
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
| | - E. Ellingwood
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - A. Erlandson
- Canadian Nuclear Laboratories Ltd, Chalk River, ON K0J 1J0 Canada
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
| | - S. S. Farahani
- Department of Physics, University of Alberta, Edmonton, AB T6G 2R3 Canada
| | | | - G. Fiorillo
- Physics Department, Università degli Studi “Federico II” di Napoli, 80126 Naples, Italy
- INFN Napoli, 80126 Naples, Italy
| | - S. Florian
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - T. Flower
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
| | - R. J. Ford
- Department of Physics and Astronomy, Laurentian University, Sudbury, ON P3E 2C6 Canada
- SNOLAB, Lively, ON P3Y 1M3 Canada
| | - R. Gagnon
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - D. Gallacher
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
| | - P. García Abia
- Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, 28040 Madrid, Spain
| | - S. Garg
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
| | - P. Giampa
- TRIUMF, Vancouver, BC V6T 2A3 Canada
| | - D. Goeldi
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
- Arthur B. McDonald Canadian Astroparticle Physics Research Institute, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - V. Golovko
- Canadian Nuclear Laboratories Ltd, Chalk River, ON K0J 1J0 Canada
| | - P. Gorel
- Department of Physics and Astronomy, Laurentian University, Sudbury, ON P3E 2C6 Canada
- SNOLAB, Lively, ON P3Y 1M3 Canada
- Arthur B. McDonald Canadian Astroparticle Physics Research Institute, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - K. Graham
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
| | - D. R. Grant
- Department of Physics, University of Alberta, Edmonton, AB T6G 2R3 Canada
| | - A. Grobov
- National Research Centre Kurchatov Institute, Moscow, 123182 Russia
- National Research Nuclear University MEPhI, Moscow, 115409 Russia
| | - A. L. Hallin
- Department of Physics, University of Alberta, Edmonton, AB T6G 2R3 Canada
| | - M. Hamstra
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
| | - P. J. Harvey
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - C. Hearns
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - T. Hugues
- AstroCeNT, Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences, Rektorska 4, 00-614 Warsaw, Poland
| | - A. Ilyasov
- National Research Centre Kurchatov Institute, Moscow, 123182 Russia
- National Research Nuclear University MEPhI, Moscow, 115409 Russia
| | - A. Joy
- Department of Physics, University of Alberta, Edmonton, AB T6G 2R3 Canada
- Arthur B. McDonald Canadian Astroparticle Physics Research Institute, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - B. Jigmeddorj
- Canadian Nuclear Laboratories Ltd, Chalk River, ON K0J 1J0 Canada
| | - C. J. Jillings
- Department of Physics and Astronomy, Laurentian University, Sudbury, ON P3E 2C6 Canada
- SNOLAB, Lively, ON P3Y 1M3 Canada
| | - O. Kamaev
- Canadian Nuclear Laboratories Ltd, Chalk River, ON K0J 1J0 Canada
| | - G. Kaur
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
| | - A. Kemp
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 Canada
- Royal Holloway University London, Egham Hill, Egham, Surrey TW20 0EX UK
| | - I. Kochanek
- INFN Laboratori Nazionali del Gran Sasso, 67100 Assergi, AQ Italy
| | - M. Kuźniak
- AstroCeNT, Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences, Rektorska 4, 00-614 Warsaw, Poland
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
- Arthur B. McDonald Canadian Astroparticle Physics Research Institute, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - M. Lai
- Physics Department, Università degli Studi di Cagliari, 09042 Cagliari, Italy
- INFN Cagliari, Cagliari, 09042 Italy
| | - S. Langrock
- Department of Physics and Astronomy, Laurentian University, Sudbury, ON P3E 2C6 Canada
- Arthur B. McDonald Canadian Astroparticle Physics Research Institute, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - B. Lehnert
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
- Present Address: Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - A. Leonhardt
- Department of Physics, Technische Universität München, 80333 Munich, Germany
| | - N. Levashko
- National Research Centre Kurchatov Institute, Moscow, 123182 Russia
- National Research Nuclear University MEPhI, Moscow, 115409 Russia
| | - X. Li
- Physics Department, Princeton University, Princeton, NJ 08544 USA
| | - J. Lidgard
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 Canada
| | | | - M. Lissia
- INFN Cagliari, Cagliari, 09042 Italy
| | - J. Lock
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
| | - G. Longo
- Physics Department, Università degli Studi “Federico II” di Napoli, 80126 Naples, Italy
- INFN Napoli, 80126 Naples, Italy
| | - I. Machulin
- National Research Centre Kurchatov Institute, Moscow, 123182 Russia
- National Research Nuclear University MEPhI, Moscow, 115409 Russia
| | - A. B. McDonald
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - T. McElroy
- Department of Physics, University of Alberta, Edmonton, AB T6G 2R3 Canada
| | - T. McGinn
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - J. B. McLaughlin
- Royal Holloway University London, Egham Hill, Egham, Surrey TW20 0EX UK
- TRIUMF, Vancouver, BC V6T 2A3 Canada
| | - R. Mehdiyev
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
| | - C. Mielnichuk
- Department of Physics, University of Alberta, Edmonton, AB T6G 2R3 Canada
| | - J. Monroe
- Royal Holloway University London, Egham Hill, Egham, Surrey TW20 0EX UK
| | - P. Nadeau
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
| | - C. Nantais
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - C. Ng
- Department of Physics, University of Alberta, Edmonton, AB T6G 2R3 Canada
| | - A. J. Noble
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - E. O’Dwyer
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - G. Oliviéro
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
- Arthur B. McDonald Canadian Astroparticle Physics Research Institute, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - C. Ouellet
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
| | - S. Pal
- Department of Physics, University of Alberta, Edmonton, AB T6G 2R3 Canada
- Arthur B. McDonald Canadian Astroparticle Physics Research Institute, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - P. Pasuthip
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - S. J. M. Peeters
- University of Sussex, Sussex House, Brighton, East Sussex BN1 9RH UK
| | - M. Perry
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
| | - V. Pesudo
- Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, 28040 Madrid, Spain
| | - E. Picciau
- Physics Department, Università degli Studi di Cagliari, 09042 Cagliari, Italy
- INFN Cagliari, Cagliari, 09042 Italy
| | - M.-C. Piro
- Department of Physics, University of Alberta, Edmonton, AB T6G 2R3 Canada
- Arthur B. McDonald Canadian Astroparticle Physics Research Institute, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - T. R. Pollmann
- Department of Physics, Technische Universität München, 80333 Munich, Germany
- Present Address: Nikhef and the University of Amsterdam, Science Park, 1098 XG Amsterdam, The Netherlands
| | - E. T. Rand
- Canadian Nuclear Laboratories Ltd, Chalk River, ON K0J 1J0 Canada
| | - C. Rethmeier
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
| | | | - I. Rodríguez-García
- Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, 28040 Madrid, Spain
| | - L. Roszkowski
- AstroCeNT, Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences, Rektorska 4, 00-614 Warsaw, Poland
- BP2, National Centre for Nuclear Research, ul. Pasteura 7, 02-093 Warsaw, Poland
| | - J. B. Ruhland
- Department of Physics, Technische Universität München, 80333 Munich, Germany
| | - E. Sánchez-García
- Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, 28040 Madrid, Spain
| | - R. Santorelli
- Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, 28040 Madrid, Spain
| | - D. Sinclair
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
| | - P. Skensved
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - B. Smith
- TRIUMF, Vancouver, BC V6T 2A3 Canada
| | - N. J. T. Smith
- Department of Physics and Astronomy, Laurentian University, Sudbury, ON P3E 2C6 Canada
- SNOLAB, Lively, ON P3Y 1M3 Canada
| | - T. Sonley
- SNOLAB, Lively, ON P3Y 1M3 Canada
- Arthur B. McDonald Canadian Astroparticle Physics Research Institute, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - J. Soukup
- Department of Physics, University of Alberta, Edmonton, AB T6G 2R3 Canada
| | - R. Stainforth
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
| | - C. Stone
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - V. Strickland
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
| | - M. Stringer
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 Canada
- Arthur B. McDonald Canadian Astroparticle Physics Research Institute, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - B. Sur
- Canadian Nuclear Laboratories Ltd, Chalk River, ON K0J 1J0 Canada
| | - J. Tang
- Department of Physics, University of Alberta, Edmonton, AB T6G 2R3 Canada
| | - E. Vázquez-Jáuregui
- Department of Physics and Astronomy, Laurentian University, Sudbury, ON P3E 2C6 Canada
- Instituto de Física, Universidad Nacional Autónoma de México, A. P. 20-364, 01000 Mexico, D.F. Mexico
| | - S. Viel
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
- Arthur B. McDonald Canadian Astroparticle Physics Research Institute, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - J. Walding
- Royal Holloway University London, Egham Hill, Egham, Surrey TW20 0EX UK
| | - M. Waqar
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
- Arthur B. McDonald Canadian Astroparticle Physics Research Institute, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - M. Ward
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - S. Westerdale
- Department of Physics, Carleton University, Ottawa, ON K1S 5B6 Canada
- INFN Cagliari, Cagliari, 09042 Italy
| | - J. Willis
- Department of Physics, University of Alberta, Edmonton, AB T6G 2R3 Canada
| | - A. Zuñiga-Reyes
- Instituto de Física, Universidad Nacional Autónoma de México, A. P. 20-364, 01000 Mexico, D.F. Mexico
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