Novel techniques for alpha/beta pulse shape discrimination in Borexino

arXiv (Cornell University)

Abstract

Borexino could efficiently distinguish between alpha and beta radiation in its liquid scintillator by the characteristic time profile of their scintillation pulse. This alpha/beta discrimination, first demonstrated at the tonne scale in the Counting Test Facility prototype, was used throughout the lifetime of the experiment between 2007 and 2021. With this method, alpha events are identified and subtracted from the beta-like solar neutrino events. This is particularly important in liquid scintillator as alpha scintillation is quenched many-fold. In Borexino, the prominent Po-210 decay peak was a background in the energy range of electrons scattered from Be-7 solar neutrinos. Optimal alpha-beta discrimination was achieved with a "multi-layer perceptron neural network", which its higher ability to leverage the timing information of the scintillation photons detected by the photomultiplier tubes. An event-by-event, high efficiency, stable, and uniform pulse shape discrimination was essential in characterising the spatial distribution of background in the detector. This benefited most Borexino measurements, including solar neutrinos in the \pp chain and the first direct observation of the CNO cycle in the Sun. This paper presents the key milestones in alpha/beta discrimination in Borexino as a term of comparison for current and future large liquid scintillator detectors

Authors 74

1. D. Basilico

   Istituto Nazionale di Fisica Nucleare, Sezione di Milano

   Affiliation as printed

   Dipartimento di Fisica, Università degli Studi e INFN, 20133 Milano, Italy

2. G. Bellini

   Istituto Nazionale di Fisica Nucleare, Sezione di Milano

   Affiliation as printed

   Dipartimento di Fisica, Università degli Studi e INFN, 20133 Milano, Italy

3. Jay B. Benziger

   Princeton University

   Affiliation as printed

   Chemical Engineering Department, Princeton University, Princeton, NJ 08544, USA

4. R. Biondi

   Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso

   Affiliation as printed

   INFN Laboratori Nazionali del Gran Sasso, 67010 Assergi (AQ), Italy

5. B. Caccianiga

   Istituto Nazionale di Fisica Nucleare, Sezione di Milano

   Affiliation as printed

   Dipartimento di Fisica, Università degli Studi e INFN, 20133 Milano, Italy

6. Frank P. Calaprice

   Princeton University

   Affiliation as printed

   Physics Department, Princeton University, Princeton, NJ 08544, USA

7. A. Caminata

   Istituto Nazionale di Fisica Nucleare, Sezione di Genova · University of Genoa

   Affiliation as printed

   Dipartimento di Fisica, Università degli Studi e INFN, 16146 Genova, Italy

8. A. Chepurnov

   Lomonosov Moscow State University · Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University

   Affiliation as printed

   Lomonosov Moscow State University Skobeltsyn Institute of Nuclear Physics, 119234 Moscow, Russia

9. Davide D'Angelo

   Istituto Nazionale di Fisica Nucleare, Sezione di Milano

   Affiliation as printed

   Dipartimento di Fisica, Università degli Studi e INFN, 20133 Milano, Italy

10. A. Derbin

    Kurchatov Institute · Petersburg Nuclear Physics Institute

    Affiliation as printed

    St. Petersburg Nuclear Physics Institute NRC Kurchatov Institute, 188350 Gatchina, Russia

11. A. Di Giacintov
12. V. Di Marcello

    Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso

    Affiliation as printed

    INFN Laboratori Nazionali del Gran Sasso, 67010 Assergi (AQ), Italy

13. Xuefeng Ding

    Princeton University

    Affiliation as printed

    Physics Department, Princeton University, Princeton, NJ 08544, USA

14. Antonio Di Ludovico
15. L. Di Noto

    Istituto Nazionale di Fisica Nucleare, Sezione di Genova · University of Genoa

    Affiliation as printed

    Dipartimento di Fisica, Università degli Studi e INFN, 16146 Genova, Italy

16. I. Drachnev

    Kurchatov Institute · Petersburg Nuclear Physics Institute

    Affiliation as printed

    St. Petersburg Nuclear Physics Institute NRC Kurchatov Institute, 188350 Gatchina, Russia

17. Davide Franco

    Centre National de la Recherche Scientifique · Commissariat à l'Énergie Atomique et aux Énergies Alternatives · Observatoire de Paris · Laboratoire AstroParticule et Cosmologie · Sorbonne Paris Cité · Institut National de Physique Nucléaire et de Physique des Particules · Institut de Recherche sur les Lois Fondamentales de l'Univers · Université Paris Diderot

    Affiliation as printed

    AstroParticule et Cosmologie, Université Paris Diderot,

    CNRS/IN2P3, CEA/IRFU, Observatoire de Paris, Sorbonne Paris Cité, 75205 Paris Cedex 13, France

18. C. Galbiati

    Princeton University · Gran Sasso Science Institute

    Affiliation as printed

    Gran Sasso Science Institute, 67100 L'Aquila, Italy

    Physics Department, Princeton University, Princeton, NJ 08544, USA

19. Chiara Ghiano

    Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso

    Affiliation as printed

    INFN Laboratori Nazionali del Gran Sasso, 67010 Assergi (AQ), Italy

20. M. Giammarchi

    Istituto Nazionale di Fisica Nucleare, Sezione di Milano

    Affiliation as printed

    Dipartimento di Fisica, Università degli Studi e INFN, 20133 Milano, Italy

21. A. Goretti

    Princeton University

    Affiliation as printed

    Physics Department, Princeton University, Princeton, NJ 08544, USA

22. Maxim Gromov

    Lomonosov Moscow State University · Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University

    Affiliation as printed

    Lomonosov Moscow State University Skobeltsyn Institute of Nuclear Physics, 119234 Moscow, Russia

23. Daniele Guffanti

    Johannes Gutenberg University Mainz

    Affiliation as printed

    Institute of Physics and Excellence Cluster PRISMA+, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany

24. Aldo Ianni

    Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso

    Affiliation as printed

    INFN Laboratori Nazionali del Gran Sasso, 67010 Assergi (AQ), Italy

25. Andrea Ianni

    Princeton University

    Affiliation as printed

    Physics Department, Princeton University, Princeton, NJ 08544, USA

26. A. Jany

    Jagiellonian University

    Affiliation as printed

    M. Smoluchowski Institute of Physics, Jagiellonian University, 30348 Krakow, Poland

27. Vladislav Kobychev

    Institute for Nuclear Research

    Affiliation as printed

    Institute for Nuclear Research of NASU, 03028 Kyiv, Ukraine

28. George Korga

    Royal Holloway University of London · HUN-REN Institute for Nuclear Research

    Affiliation as printed

    Department of Physics, Royal Holloway University of London, Egham, Surrey,TW20 0EX, UK

    Institute of Nuclear Research (Atomki), Debrecen, Hungary

29. Sindhujha Kumaran Aachen III. Physikalisches Institut B

    Forschungszentrum Jülich · Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso · RWTH Aachen University

    Affiliation as printed

    RWTH Aachen

    III. Physikalisches Institut B, RWTH Aachen University, 52062 Aachen, Germany

    INFN Laboratori Nazionali del Gran Sasso, 67010 Assergi (AQ), Italy

    Institut für Kernphysik, Forschungszentrum Jülich, 52425 Jülich, Germany

30. Matthias Laubenstein

    Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso

    Affiliation as printed

    INFN Laboratori Nazionali del Gran Sasso, 67010 Assergi (AQ), Italy

31. E. A. Litvinovich

    Kurchatov Institute · National Research Nuclear University MEPhI

    Affiliation as printed

    National Research Centre Kurchatov Institute, 123182 Moscow, Russia

    National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 115409 Moscow, Russia

32. P. Lombardi

    Istituto Nazionale di Fisica Nucleare, Sezione di Milano

    Affiliation as printed

    Dipartimento di Fisica, Università degli Studi e INFN, 20133 Milano, Italy

33. I. Lomskaya

    Kurchatov Institute · Petersburg Nuclear Physics Institute

    Affiliation as printed

    St. Petersburg Nuclear Physics Institute NRC Kurchatov Institute, 188350 Gatchina, Russia

34. L. Ludhová Aachen III. Physikalisches Institut B

    Forschungszentrum Jülich · RWTH Aachen University

    Affiliation as printed

    RWTH Aachen

    III. Physikalisches Institut B, RWTH Aachen University, 52062 Aachen, Germany

    Institut für Kernphysik, Forschungszentrum Jülich, 52425 Jülich, Germany

35. I. Machulin

    Kurchatov Institute · National Research Nuclear University MEPhI

    Affiliation as printed

    National Research Centre Kurchatov Institute, 123182 Moscow, Russia

    National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 115409 Moscow, Russia

36. J. Martýn

    Johannes Gutenberg University Mainz

    Affiliation as printed

    Institute of Physics and Excellence Cluster PRISMA+, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany

37. E. Meroni

    Istituto Nazionale di Fisica Nucleare, Sezione di Milano

    Affiliation as printed

    Dipartimento di Fisica, Università degli Studi e INFN, 20133 Milano, Italy

38. L. Miramonti

    Istituto Nazionale di Fisica Nucleare, Sezione di Milano

    Affiliation as printed

    Dipartimento di Fisica, Università degli Studi e INFN, 20133 Milano, Italy

39. M. Misiaszek

    Jagiellonian University

    Affiliation as printed

    M. Smoluchowski Institute of Physics, Jagiellonian University, 30348 Krakow, Poland

40. Valentina Muratova

    Kurchatov Institute · Petersburg Nuclear Physics Institute

    Affiliation as printed

    St. Petersburg Nuclear Physics Institute NRC Kurchatov Institute, 188350 Gatchina, Russia

41. Нугманов Радик Рафаэльевич

    Kurchatov Institute

    Affiliation as printed

    National Research Centre Kurchatov Institute, 123182 Moscow, Russia

42. L. Oberauer

    Technical University of Munich

    Affiliation as printed

    Physik-Department, Technische Universität München, 85748 Garching, Germany

43. V. Orekhov

    Johannes Gutenberg University Mainz

    Affiliation as printed

    Institute of Physics and Excellence Cluster PRISMA+, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany

44. F. Ortica

    University of Perugia · Istituto Nazionale di Fisica Nucleare, Sezione di Perugia

    Affiliation as printed

    Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi e INFN, 06123 Perugia, Italy

45. M. Pallavicini

    Istituto Nazionale di Fisica Nucleare, Sezione di Genova · University of Genoa

    Affiliation as printed

    Dipartimento di Fisica, Università degli Studi e INFN, 16146 Genova, Italy

46. Luca Pelicci Aachen III. Physikalisches Institut B

    Forschungszentrum Jülich · RWTH Aachen University

    Affiliation as printed

    RWTH Aachen

    III. Physikalisches Institut B, RWTH Aachen University, 52062 Aachen, Germany

    Institut für Kernphysik, Forschungszentrum Jülich, 52425 Jülich, Germany

47. Ö. Penek

    Forschungszentrum Jülich

    Affiliation as printed

    Institut für Kernphysik, Forschungszentrum Jülich, 52425 Jülich, Germany

48. L. Pietrofaccia

    Princeton University

    Affiliation as printed

    Physics Department, Princeton University, Princeton, NJ 08544, USA

49. N. Pilipenko

    Kurchatov Institute · Petersburg Nuclear Physics Institute

    Affiliation as printed

    St. Petersburg Nuclear Physics Institute NRC Kurchatov Institute, 188350 Gatchina, Russia

50. Andrea Pietro Pocar

    University of Massachusetts Amherst

    Affiliation as printed

    Amherst Center for Fundamental Interactions and Physics Department, University of Massachusetts, Amherst, MA 01003, USA

51. G. Raikov

    Kurchatov Institute

    Affiliation as printed

    National Research Centre Kurchatov Institute, 123182 Moscow, Russia

52. Maria Teresa Ranalli

    Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso

    Affiliation as printed

    INFN Laboratori Nazionali del Gran Sasso, 67010 Assergi (AQ), Italy

53. G. Ranucci

    Istituto Nazionale di Fisica Nucleare, Sezione di Milano

    Affiliation as printed

    Dipartimento di Fisica, Università degli Studi e INFN, 20133 Milano, Italy

54. A. Razeto

    Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso

    Affiliation as printed

    INFN Laboratori Nazionali del Gran Sasso, 67010 Assergi (AQ), Italy

55. Alessandra Carlotta Re

    Istituto Nazionale di Fisica Nucleare, Sezione di Milano

    Affiliation as printed

    Dipartimento di Fisica, Università degli Studi e INFN, 20133 Milano, Italy

56. N. Rossi

    Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso

    Affiliation as printed

    INFN Laboratori Nazionali del Gran Sasso, 67010 Assergi (AQ), Italy

57. S. Schoenert

    Technical University of Munich

    Affiliation as printed

    Physik-Department, Technische Universität München, 85748 Garching, Germany

58. D. Semenov

    Kurchatov Institute · Petersburg Nuclear Physics Institute

    Affiliation as printed

    St. Petersburg Nuclear Physics Institute NRC Kurchatov Institute, 188350 Gatchina, Russia

59. G. Settanta

    Forschungszentrum Jülich

    Affiliation as printed

    Institut für Kernphysik, Forschungszentrum Jülich, 52425 Jülich, Germany

60. Mikhail Skorokhvatov

    Kurchatov Institute · National Research Nuclear University MEPhI

    Affiliation as printed

    National Research Centre Kurchatov Institute, 123182 Moscow, Russia

    National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 115409 Moscow, Russia

61. A. Singhal Aachen III. Physikalisches Institut B

    Forschungszentrum Jülich · RWTH Aachen University

    Affiliation as printed

    RWTH Aachen

    III. Physikalisches Institut B, RWTH Aachen University, 52062 Aachen, Germany

    Institut für Kernphysik, Forschungszentrum Jülich, 52425 Jülich, Germany

62. Oleg Smirnov

    Joint Institute for Nuclear Research

    Affiliation as printed

    Joint Institute for Nuclear Research, 141980 Dubna, Russia

63. A. Sotnikov

    GSI Helmholtz Centre for Heavy Ion Research · University of California, Irvine · Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso · Istituto Superiore per la Protezione e la Ricerca Ambientale · Institute of High Energy Physics · Istituto Nazionale di Fisica Nucleare, Sezione di Milano Bicocca · Max Planck Institute for Nuclear Physics · University of Milano-Bicocca

    Affiliation as printed

    Department of Physics and Astronomy, University of California, Irvine, California, USA

    Dipartimento di Fisica, Università degli Studi e INFN Milano-Bicocca, 20126 Milano, Italy

    GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany

    IHEP Institute of High Energy Physics, 100049 Beijing, China

    INFN Laboratori Nazionali del Gran Sasso, 67010 Assergi (AQ), Italy

    Istituto Superiore per la Protezione e la Ricerca Ambientale, 00144 Roma, Italy

    Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany

64. Roberto Tartaglia

    Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso

    Affiliation as printed

    INFN Laboratori Nazionali del Gran Sasso, 67010 Assergi (AQ), Italy

65. G. Testera

    GSI Helmholtz Centre for Heavy Ion Research · University of California, Irvine · Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso · Istituto Superiore per la Protezione e la Ricerca Ambientale · Institute of High Energy Physics · Istituto Nazionale di Fisica Nucleare, Sezione di Milano Bicocca · Max Planck Institute for Nuclear Physics · University of Milano-Bicocca

    Affiliation as printed

    Department of Physics and Astronomy, University of California, Irvine, California, USA

    Dipartimento di Fisica, Università degli Studi e INFN Milano-Bicocca, 20126 Milano, Italy

    GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany

    IHEP Institute of High Energy Physics, 100049 Beijing, China

    INFN Laboratori Nazionali del Gran Sasso, 67010 Assergi (AQ), Italy

    Istituto Superiore per la Protezione e la Ricerca Ambientale, 00144 Roma, Italy

    Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany

66. E. Unzhakov

    GSI Helmholtz Centre for Heavy Ion Research · University of California, Irvine · Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso · Istituto Superiore per la Protezione e la Ricerca Ambientale · Institute of High Energy Physics · Istituto Nazionale di Fisica Nucleare, Sezione di Milano Bicocca · Max Planck Institute for Nuclear Physics · University of Milano-Bicocca

    Affiliation as printed

    Department of Physics and Astronomy, University of California, Irvine, California, USA

    Dipartimento di Fisica, Università degli Studi e INFN Milano-Bicocca, 20126 Milano, Italy

    GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany

    IHEP Institute of High Energy Physics, 100049 Beijing, China

    INFN Laboratori Nazionali del Gran Sasso, 67010 Assergi (AQ), Italy

    Istituto Superiore per la Protezione e la Ricerca Ambientale, 00144 Roma, Italy

    Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany

67. A. Vishneva

    GSI Helmholtz Centre for Heavy Ion Research · University of California, Irvine · Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso · Istituto Superiore per la Protezione e la Ricerca Ambientale · Institute of High Energy Physics · Istituto Nazionale di Fisica Nucleare, Sezione di Milano Bicocca · Max Planck Institute for Nuclear Physics · University of Milano-Bicocca

    Affiliation as printed

    Department of Physics and Astronomy, University of California, Irvine, California, USA

    Dipartimento di Fisica, Università degli Studi e INFN Milano-Bicocca, 20126 Milano, Italy

    GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany

    IHEP Institute of High Energy Physics, 100049 Beijing, China

    INFN Laboratori Nazionali del Gran Sasso, 67010 Assergi (AQ), Italy

    Istituto Superiore per la Protezione e la Ricerca Ambientale, 00144 Roma, Italy

    Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany

68. R. B. Vogelaar

    Virginia Tech

    Affiliation as printed

    Physics Department, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA

69. F. von Feilitzsch

    Technical University of Munich

    Affiliation as printed

    Physik-Department, Technische Universität München, 85748 Garching, Germany

70. Marek Janusz Wójcik

    Jagiellonian University

    Affiliation as printed

    M. Smoluchowski Institute of Physics, Jagiellonian University, 30348 Krakow, Poland

71. Matthias Christian Wurm

    Johannes Gutenberg University Mainz

    Affiliation as printed

    Institute of Physics and Excellence Cluster PRISMA+, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany

72. Sandra Zavatarelli

    GSI Helmholtz Centre for Heavy Ion Research · University of California, Irvine · Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso · Istituto Superiore per la Protezione e la Ricerca Ambientale · Institute of High Energy Physics · Istituto Nazionale di Fisica Nucleare, Sezione di Milano Bicocca · Max Planck Institute for Nuclear Physics · University of Milano-Bicocca

    Affiliation as printed

    Department of Physics and Astronomy, University of California, Irvine, California, USA

    Dipartimento di Fisica, Università degli Studi e INFN Milano-Bicocca, 20126 Milano, Italy

    GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany

    IHEP Institute of High Energy Physics, 100049 Beijing, China

    INFN Laboratori Nazionali del Gran Sasso, 67010 Assergi (AQ), Italy

    Istituto Superiore per la Protezione e la Ricerca Ambientale, 00144 Roma, Italy

    Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany

73. K. Zuber

    Technische Universität Dresden

    Affiliation as printed

    Department of Physics, Technische Universität Dresden, 01062 Dresden, Germany

74. G. Zuzel

    GSI Helmholtz Centre for Heavy Ion Research · University of California, Irvine · Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso · Istituto Superiore per la Protezione e la Ricerca Ambientale · Institute of High Energy Physics · Istituto Nazionale di Fisica Nucleare, Sezione di Milano Bicocca · Max Planck Institute for Nuclear Physics · University of Milano-Bicocca

    Affiliation as printed

    Department of Physics and Astronomy, University of California, Irvine, California, USA

    Dipartimento di Fisica, Università degli Studi e INFN Milano-Bicocca, 20126 Milano, Italy

    GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany

    IHEP Institute of High Energy Physics, 100049 Beijing, China

    INFN Laboratori Nazionali del Gran Sasso, 67010 Assergi (AQ), Italy

    Istituto Superiore per la Protezione e la Ricerca Ambientale, 00144 Roma, Italy

    Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany