First Directional Measurement of Sub-MeV Solar Neutrinos with Borexino

UCL Discovery (University College London)

Abstract

We report the measurement of sub-MeV solar neutrinos through the use of their associated Cherenkov radiation, performed with the Borexino detector at the Laboratori Nazionali del Gran Sasso. The measurement is achieved using a novel technique that correlates individual photon hits of events to the known position of the Sun. In an energy window between 0.54 to 0.74 MeV, selected using the \ndominant scintillation light, we have measured 10 887þ2386 ðstatÞ � 947ðsystÞ (68% confidence interval) −2103 solar neutrinos out of 19904 total events. This corresponds to a 7Be neutrino interaction rate of 51.6þ13.9 counts=ðday · 100 tonÞ, which is in agreement with the standard solar model predictions and the −12.5 previous spectroscopic results of Borexino. The no-neutrino hypothesis can be excluded with > 5σ confidence level. For the first time, we have demonstrated the possibility of utilizing the directional Cherenkov information for sub-MeV solar neutrinos, in a large-scale, high light yield liquid scintillator detector. This measurement provides an experimental proof of principle for future hybrid event reconstruction using both Cherenkov and scintillation signatures simultaneously.

Authors 98

1. M. Agostini

   University College London · Technical University of Munich

   Affiliation as printed

   Department of Physics and Astronomy, University College London, London, WC1E 6BT, United Kingdom

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

2. K. Altenmüller

   Technical University of Munich

   Affiliation as printed

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

3. B. Caccianiga

   Technical University of Munich

   Affiliation as printed

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

4. Frank P. Calaprice

   Kurchatov Institute

   Affiliation as printed

   National Research Centre Kurchatov Institute, 123182 Moscow, Russia

5. A Caminata

   Forschungszentrum Jülich

   Affiliation as printed

   Institut für Kernphysik, Forschungszentrum Jülich, 52425 Jülich, Germany

6. P. Cavalcante

   Istituto Nazionale di Fisica Nucleare, Sezione di Milano

   Affiliation as printed

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

7. A. Chepurnov

   Istituto Nazionale di Fisica Nucleare, Sezione di Milano

   Affiliation as printed

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

8. D. D'Angelo

   Princeton University

   Affiliation as printed

   Chemical Engineering Department, Princeton University, Princeton, New Jersey 08544, USA

9. S. Davini

   Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso

   Affiliation as printed

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

10. A. Derbin

    Istituto Nazionale di Fisica Nucleare, Sezione di Milano

    Affiliation as printed

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

11. A. Di Giacinto

    Istituto Nazionale di Fisica Nucleare, Sezione di Milano

    Affiliation as printed

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

12. V. Di Marcello

    Princeton University

    Affiliation as printed

    Physics Department, Princeton University, Princeton, New Jersey 08544, USA

13. S. Appel

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

    Affiliation as printed

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

14. X. F. Ding

    Virginia Tech

    Affiliation as printed

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

15. A. Di Ludovico

    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

16. L. Di Noto

    Istituto Nazionale di Fisica Nucleare, Sezione di Milano

    Affiliation as printed

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

17. I. Drachnev

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

    Affiliation as printed

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

18. A. Formozov

    Kurchatov Institute · Petersburg Nuclear Physics Institute

    Affiliation as printed

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

19. D. Franco

    Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso

    Affiliation as printed

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

20. C. Galbiati

    Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso

    Affiliation as printed

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

21. Chiara Ghiano

    Princeton University

    Affiliation as printed

    Physics Department, Princeton University, Princeton, New Jersey 08544, USA

22. M. Giammarchi

    Princeton University

    Affiliation as printed

    Physics Department, Princeton University, Princeton, New Jersey 08544, USA

23. A. Goretti

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

    Affiliation as printed

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

24. Victor Atroshchenko

    Kurchatov Institute · Petersburg Nuclear Physics Institute

    Affiliation as printed

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

25. A. S. Göttel

    Istituto Nazionale di Fisica Nucleare, Sezione di Milano · Joint Institute for Nuclear Research

    Affiliation as printed

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

    Joint Institute for Nuclear Research, 141980 Dubna, Russia

26. M. Gromov

    Centre National de la Recherche Scientifique · Université Paris Cité

    Affiliation as printed

    APC, Université de Paris, CNRS, Astroparticule et Cosmologie, Paris F-75013, France

27. D. Guffanti

    Princeton University · Gran Sasso Science Institute

    Affiliation as printed

    Gran Sasso Science Institute, 67100 L'Aquila, Italy

    Physics Department, Princeton University, Princeton, New Jersey 08544, USA

28. 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

29. Andrea Ianni

    Istituto Nazionale di Fisica Nucleare, Sezione di Milano

    Affiliation as printed

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

30. A. Jany

    Princeton University · Jagiellonian University

    Affiliation as printed

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

    Physics Department, Princeton University, Princeton, New Jersey 08544, USA

31. Dominik Jeschke Aachen III. Physikalisches Institut B

    RWTH Aachen University · Forschungszentrum Jülich

    Affiliation as printed

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

    Institut für Kernphysik, Forschungszentrum Jülich, 52425 Jülich, Germany

32. V. Kobychev

    Lomonosov Moscow State University · Joint Institute for Nuclear Research · Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University

    Affiliation as printed

    Joint Institute for Nuclear Research, 141980 Dubna, Russia

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

33. George Korga

    Johannes Gutenberg University Mainz

    Affiliation as printed

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

34. S. Kumaran

    Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso

    Affiliation as printed

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

35. Z. Bagdasarian

    Princeton University

    Affiliation as printed

    Physics Department, Princeton University, Princeton, New Jersey 08544, USA

36. M. Laubenstein

    Jagiellonian University

    Affiliation as printed

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

37. E. Litvinovich

    Technical University of Munich

    Affiliation as printed

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

38. P. Lombardi

    Institute for Nuclear Research

    Affiliation as printed

    Institute for Nuclear Research of NAS Ukraine, 03028 Kyiv, Ukraine

39. I. Lomskaya

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

    Affiliation as printed

    Department of Physics, School of Engineering, Physical and Mathematical Sciences, Royal Holloway, University of London, Egham, TW20 OEX, United Kingdom

    Institute of Nuclear Research (Atomki), 4026, Debrecen, Hungary

40. L. Ludhová Aachen III. Physikalisches Institut B

    RWTH Aachen University · Forschungszentrum Jülich

    Affiliation as printed

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

    Institut für Kernphysik, Forschungszentrum Jülich, 52425 Jülich, Germany

41. G. Lukyanchenko

    Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso

    Affiliation as printed

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

42. L. Lukyanchenko

    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

43. Igor Machulin

    Istituto Nazionale di Fisica Nucleare, Sezione di Milano

    Affiliation as printed

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

44. J. Martyn

    Kurchatov Institute · Petersburg Nuclear Physics Institute

    Affiliation as printed

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

45. E. Meroni Aachen III. Physikalisches Institut B

    RWTH Aachen University · Forschungszentrum Jülich

    Affiliation as printed

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

    Institut für Kernphysik, Forschungszentrum Jülich, 52425 Jülich, Germany

46. D. Basilico

    Kurchatov Institute

    Affiliation as printed

    National Research Centre Kurchatov Institute, 123182 Moscow, Russia

47. M. Meyer

    Kurchatov Institute

    Affiliation as printed

    National Research Centre Kurchatov Institute, 123182 Moscow, Russia

48. L. Miramonti

    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

49. M. Misiaszek

    Johannes Gutenberg University Mainz

    Affiliation as printed

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

50. V. Muratova

    Istituto Nazionale di Fisica Nucleare, Sezione di Milano

    Affiliation as printed

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

51. B. Neumair

    Technische Universität Dresden

    Affiliation as printed

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

52. M. Nieslony

    Istituto Nazionale di Fisica Nucleare, Sezione di Milano

    Affiliation as printed

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

53. Нугманов Радик Рафаэльевич

    Jagiellonian University

    Affiliation as printed

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

54. L. Oberauer

    Kurchatov Institute · Petersburg Nuclear Physics Institute

    Affiliation as printed

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

55. V. Orekhov

    Technical University of Munich

    Affiliation as printed

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

56. F. Ortica

    Johannes Gutenberg University Mainz

    Affiliation as printed

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

57. G. Bellini

    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

58. Marco Pallavicini

    Technical University of Munich

    Affiliation as printed

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

59. L. Papp

    Johannes Gutenberg University Mainz

    Affiliation as printed

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

60. L. Pelicci

    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

61. O. Penek

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

    Affiliation as printed

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

62. L. Pietrofaccia

    Technical University of Munich

    Affiliation as printed

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

63. N. Pilipenko Aachen III. Physikalisches Institut B

    RWTH Aachen University · Forschungszentrum Jülich

    Affiliation as printed

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

    Institut für Kernphysik, Forschungszentrum Jülich, 52425 Jülich, Germany

64. A. Pocar

    Forschungszentrum Jülich

    Affiliation as printed

    Institut für Kernphysik, Forschungszentrum Jülich, 52425 Jülich, Germany

65. Georgy Raikov

    Princeton University

    Affiliation as printed

    Physics Department, Princeton University, Princeton, New Jersey 08544, USA

66. Maria Teresa Ranalli

    Kurchatov Institute · Petersburg Nuclear Physics Institute

    Affiliation as printed

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

67. G. Ranucci

    University of Massachusetts Amherst

    Affiliation as printed

    Amherst Center for Fundamental Interactions and Physics Department, UMass, Amherst, Massachusetts 01003, USA

68. J. Benziger

    Kurchatov Institute

    Affiliation as printed

    National Research Centre Kurchatov Institute, 123182 Moscow, Russia

69. 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

70. A. Re

    Istituto Nazionale di Fisica Nucleare, Sezione di Milano

    Affiliation as printed

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

71. M. Redchuk

    Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso

    Affiliation as printed

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

72. A. Romani

    Istituto Nazionale di Fisica Nucleare, Sezione di Milano

    Affiliation as printed

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

73. N. Rossi Aachen III. Physikalisches Institut B

    RWTH Aachen University · Forschungszentrum Jülich

    Affiliation as printed

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

    Institut für Kernphysik, Forschungszentrum Jülich, 52425 Jülich, Germany

74. S. Schönert

    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

75. D. Semenov

    Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso

    Affiliation as printed

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

76. G. Settanta

    Technical University of Munich

    Affiliation as printed

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

77. Mikhail Skorokhvatov

    Kurchatov Institute · Petersburg Nuclear Physics Institute

    Affiliation as printed

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

78. A. Singhal

    Forschungszentrum Jülich

    Affiliation as printed

    Institut für Kernphysik, Forschungszentrum Jülich, 52425 Jülich, Germany

79. R. Biondi

    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

80. O. Smirnov Aachen III. Physikalisches Institut B

    RWTH Aachen University · Forschungszentrum Jülich

    Affiliation as printed

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

    Institut für Kernphysik, Forschungszentrum Jülich, 52425 Jülich, Germany

81. A. Sotnikov

    Joint Institute for Nuclear Research

    Affiliation as printed

    Joint Institute for Nuclear Research, 141980 Dubna, Russia

82. Y. Suvorov

    Joint Institute for Nuclear Research

    Affiliation as printed

    Joint Institute for Nuclear Research, 141980 Dubna, Russia

83. Roberto Tartaglia

    Kurchatov Institute · Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso

    Affiliation as printed

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

    National Research Centre Kurchatov Institute, 123182 Moscow, Russia

84. G. Testera

    Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso

    Affiliation as printed

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

85. J. Thurn

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

    Affiliation as printed

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

86. E. Unzhakov

    Technische Universität Dresden

    Affiliation as printed

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

87. A. Vishneva

    Kurchatov Institute · Petersburg Nuclear Physics Institute

    Affiliation as printed

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

88. R. B. Vogelaar

    Joint Institute for Nuclear Research

    Affiliation as printed

    Joint Institute for Nuclear Research, 141980 Dubna, Russia

89. F. von Feilitzsch

    Virginia Tech

    Affiliation as printed

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

90. D. Bravo

    Technical University of Munich

    Affiliation as printed

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

91. A. Wessel Aachen III. Physikalisches Institut B

    RWTH Aachen University · Forschungszentrum Jülich · GSI Helmholtz Centre for Heavy Ion Research

    Affiliation as printed

    GSI Helmholtzzentrum für Schwerionenforschung, Planckstrasse 1, D-64291 Darmstadt, Germany

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

    Institut für Kernphysik, Forschungszentrum Jülich, 52425 Jülich, Germany

92. M. Wójcik

    Jagiellonian University

    Affiliation as printed

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

93. B. Wonsak

    Universität Hamburg

    Affiliation as printed

    University of Hamburg, Institute of Experimental Physics, Luruper Chaussee 149, 22761 Hamburg, Germany

94. Matthias Christian Wurm

    Johannes Gutenberg University Mainz

    Affiliation as printed

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

95. Sandra Zavatarelli

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

    Affiliation as printed

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

96. Kai Zuber

    Technische Universität Dresden

    Affiliation as printed

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

97. G. Zuzel

    Jagiellonian University

    Affiliation as printed

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

98. Borexino Collaboration