Search for the Lepton-Flavor Violating Decays B + → π + μ ± e ∓

Physical Review Letters, vol. 137, pp. 061802

Abstract

The first search for the lepton-flavor violating decays B^{+}→π^{+}μ^{±}e^{∓} in proton-proton collisions is presented, using data collected by the LHCb experiment between 2011 and 2018, corresponding to an integrated luminosity of 9 fb^{-1}. No significant signal is observed and an upper limit on the branching fraction is set at B(B^{+}→π^{+}μ^{±}e^{∓})<1.8×10^{-9} at the 90% confidence level, 2 orders of magnitude more restrictive than the most stringent upper limit to date. This is the first constraint on lepton-flavor violating b→d quark transitions at the LHC and also sets the most stringent upper limits to date on b→dμ^{±}e^{∓} transitions. Limits on left-handed and scalar scenarios beyond the standard model are also reported.

Authors 99

1. R. Aaij

   National Institute for Subatomic Physics

   Affiliation as printed

   Nikhef National Institute for Subatomic Physics

2. M. Abdelfatah

   Syracuse University

   Affiliation as printed

   Syracuse University

3. A. S. W. Abdelmotteleb

   University of Warwick

   Affiliation as printed

   University of Warwick

4. Carlos Abellán Beteta

   University of Zurich

   Affiliation as printed

   Universität Zürich

5. C. Abellán Beteta

   University of Edinburgh

   Affiliation as printed

   University of Edinburgh

6. T. Ackernley

   University of Liverpool

   Affiliation as printed

   University of Liverpool

7. A. A. Adefisoye

   Syracuse University

   Affiliation as printed

   Syracuse University

8. B. Adeva

   Universidade de Santiago de Compostela

   Affiliation as printed

   Universidade de Santiago de Compostela

9. M. Adinolfi

   University of Bristol

   Affiliation as printed

   University of Bristol

10. P. Adlarson

    Uppsala University · National Centre for Nuclear Research · University of Glasgow

    Affiliation as printed

    National Center for Nuclear Research (NCBJ)

    University of Glasgow

    Uppsala University

11. C. Agapopoulou

    Université Paris-Saclay

    Affiliation as printed

    Université Paris-Saclay

12. C. Aidala

    University of Michigan · Syracuse University

    Affiliation as printed

    Syracuse University

    University of Michigan

13. S. Akar

    Université Clermont Auvergne

    Affiliation as printed

    Université Clermont Auvergne

14. K. Carvalho Akiba

    National Institute for Subatomic Physics

    Affiliation as printed

    Nikhef National Institute for Subatomic Physics

15. P. Albicocco

    Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati

    Affiliation as printed

    INFN Laboratori Nazionali di Frascati

16. J. Albrecht

    TU Dortmund University

    Affiliation as printed

    Technische Universität Dortmund

17. R. Aleksiejūnas

    University of Freiburg · Vilnius University

    Affiliation as printed

    Albert-Ludwigs-Universität Freiburg

    Vilnius University

18. F. Alessio

    European Organization for Nuclear Research

    Affiliation as printed

    European Organization for Nuclear Research (CERN)

19. P. Álvarez Cartelle

    Universidade de Santiago de Compostela

    Affiliation as printed

    Universidade de Santiago de Compostela

20. S. Amato

    Universidade Federal do Rio de Janeiro

    Affiliation as printed

    Universidade Federal do Rio de Janeiro (UFRJ)

21. Y. Amhis

    Université Paris-Saclay

    Affiliation as printed

    Université Paris-Saclay

22. Liupan An

    Peking University

    Affiliation as printed

    Peking University

23. L. Anderlini

    Istituto Nazionale di Fisica Nucleare, Sezione di Firenze

    Affiliation as printed

    INFN Sezione di Firenze

24. M. Andersson

    University of Zurich

    Affiliation as printed

    Universität Zürich

25. P. Andreola

    University of Zurich

    Affiliation as printed

    Universität Zürich

26. M. Andreotti

    Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara

    Affiliation as printed

    INFN Sezione di Ferrara

27. Sergio Andres Estrada

    Universidade da Coruña

    Affiliation as printed

    Universidade da Coruña

28. Alessia Anelli

    Istituto Nazionale di Fisica Nucleare, Sezione di Milano Bicocca

    Affiliation as printed

    INFN Sezione di Milano-Bicocca

29. D. Ao

    University of Chinese Academy of Sciences

    Affiliation as printed

    University of Chinese Academy of Sciences

30. C. Arata

    Université Paris-Saclay

    Affiliation as printed

    Université Paris-Saclay

31. F. Archilli

    Istituto Nazionale di Fisica Nucleare, Roma Tor Vergata

    Affiliation as printed

    INFN Sezione di Roma Tor Vergata

32. Zaratsyan Areg

    Syracuse University

    Affiliation as printed

    Syracuse University

33. Matteo Argenton

    Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara

    Affiliation as printed

    INFN Sezione di Ferrara

34. S. Arguedas Cuendis

    Consejo Nacional de Rectores · European Organization for Nuclear Research

    Affiliation as printed

    Consejo Nacional de Rectores (CONARE)

    European Organization for Nuclear Research (CERN)

35. Lisa Arnone

    Istituto Nazionale di Fisica Nucleare, Sezione di Milano Bicocca

    Affiliation as printed

    INFN Sezione di Milano-Bicocca

36. M. Artuso

    Syracuse University

    Affiliation as printed

    Syracuse University

37. E. Aslanides

    Aix-Marseille Université

    Affiliation as printed

    Aix Marseille Univ

38. R. Ataíde Da Silva
    Affiliation as printed

    Institute of Physics

39. M. Atzeni

    Massachusetts Institute of Technology

    Affiliation as printed

    Massachusetts Institute of Technology

40. B. Audurier

    Université Paris-Saclay

    Affiliation as printed

    Université Paris-Saclay

41. Juliette Authier

    Laboratoire Leprince-Ringuet

    Affiliation as printed

    Laboratoire Leprince-Ringuet

42. D. Bacher

    University of Oxford

    Affiliation as printed

    University of Oxford

43. I. Bachiller
    Affiliation as printed

    Institute of Physics

44. S. Bachmann

    Heidelberg University

    Affiliation as printed

    Ruprecht-Karls-Universität Heidelberg

45. Marie Bachmayer
    Affiliation as printed

    Institute of Physics

46. John J Back

    University of Warwick

    Affiliation as printed

    University of Warwick

47. Z. B. Bai

    Central China Normal University

    Affiliation as printed

    Central China Normal University

48. V. Balagura

    Laboratoire Leprince-Ringuet

    Affiliation as printed

    Laboratoire Leprince-Ringuet

49. A Balboni

    Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara

    Affiliation as printed

    INFN Sezione di Ferrara

50. W. Baldini

    Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara

    Affiliation as printed

    INFN Sezione di Ferrara

51. Zachary Baldwin

    TU Dortmund University · Ruhr University Bochum

    Affiliation as printed

    Ruhr Universitaet Bochum

    Technische Universität Dortmund

52. Luca Balzani

    TU Dortmund University

    Affiliation as printed

    Technische Universität Dortmund

53. H. Bao

    University of Chinese Academy of Sciences

    Affiliation as printed

    University of Chinese Academy of Sciences

54. J. Baptista de Souza Leite

    Centro Brasileiro de Pesquisas Físicas

    Affiliation as printed

    Centro Brasileiro de Pesquisas Físicas (CBPF)

55. C. Barbero Pretel

    Universidade de Santiago de Compostela · Université Paris-Saclay

    Affiliation as printed

    Universidade de Santiago de Compostela

    Université Paris-Saclay

56. M. Barbetti

    Istituto Nazionale di Fisica Nucleare, Sezione di Firenze

    Affiliation as printed

    INFN Sezione di Firenze

57. I. R. Barbosa

    Universidade Federal do Rio de Janeiro · Pontifícia Universidade Católica do Rio de Janeiro

    Affiliation as printed

    Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio)

    Universidade Federal do Rio de Janeiro (UFRJ)

58. Roger John Barlow

    University of Manchester

    Affiliation as printed

    University of Manchester

59. Mikhail Barnyakov

    Istituto Nazionale di Fisica Nucleare, Sezione di Bologna

    Affiliation as printed

    INFN Sezione di Bologna

60. S. Baron

    European Organization for Nuclear Research

    Affiliation as printed

    European Organization for Nuclear Research (CERN)

61. S. Barsuk

    Université Paris-Saclay

    Affiliation as printed

    Université Paris-Saclay

62. W. Barter

    University of Edinburgh

    Affiliation as printed

    University of Edinburgh

63. W. Barter

    Syracuse University

    Affiliation as printed

    Syracuse University

64. B. Batsukh

    AGH University of Krakow

    Affiliation as printed

    AGH—University of Krakow

65. B. Batsukh

    Mongolian Academy of Sciences · Institute for High Energy Physics · Institute of High Energy Physics

    Affiliation as printed

    Institute Of High Energy Physics (IHEP)

    Mongolian Academy of Sciences

66. Piera Battista

    Université Paris-Saclay

    Affiliation as printed

    Université Paris-Saclay

67. Ali Bavarchee

    Eötvös Loránd University · European Organization for Nuclear Research

    Affiliation as printed

    Eotvos Lorand University

    European Organization for Nuclear Research (CERN)

68. A. Bay
    Affiliation as printed

    Institute of Physics

69. A. Beck

    Massachusetts Institute of Technology

    Affiliation as printed

    Massachusetts Institute of Technology

70. M. Becker

    TU Dortmund University

    Affiliation as printed

    Technische Universität Dortmund

71. F. Bedeschi

    Istituto Nazionale di Fisica Nucleare, Sezione di Pisa

    Affiliation as printed

    INFN Sezione di Pisa

72. I. Bediaga

    Centro Brasileiro de Pesquisas Físicas

    Affiliation as printed

    Centro Brasileiro de Pesquisas Físicas (CBPF)

73. Noah Albin Behling

    TU Dortmund University

    Affiliation as printed

    Technische Universität Dortmund

74. S. Belin

    Universidade de Santiago de Compostela

    Affiliation as printed

    Universidade de Santiago de Compostela

75. Alberto Bellavista

    Istituto Nazionale di Fisica Nucleare, Sezione di Bologna

    Affiliation as printed

    INFN Sezione di Bologna

76. I. Belov

    Istituto Nazionale di Fisica Nucleare, Sezione di Genova

    Affiliation as printed

    INFN Sezione di Genova

77. I. Belyaev

    Istituto Nazionale di Fisica Nucleare, Sezione di Roma I

    Affiliation as printed

    INFN Sezione di Roma La Sapienza

78. G. Bencivenni

    Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati

    Affiliation as printed

    INFN Laboratori Nazionali di Frascati

79. E. Ben-Haim

    Sorbonne Université

    Affiliation as printed

    Sorbonne Université

80. Julie Berkey

    Los Alamos National Laboratory

    Affiliation as printed

    Los Alamos National Laboratory (LANL)

81. R. Bernet

    University of Zurich

    Affiliation as printed

    Universität Zürich

82. A. Bertolin

    Istituto Nazionale di Fisica Nucleare, Sezione di Padova

    Affiliation as printed

    INFN Sezione di Padova

83. F. Betti

    University of Edinburgh

    Affiliation as printed

    University of Edinburgh

84. J. Bex

    University of Cambridge

    Affiliation as printed

    University of Cambridge

85. Oleg Bezshyyko

    Taras Shevchenko National University of Kyiv · Université Paris-Saclay

    Affiliation as printed

    Taras Schevchenko University of Kyiv

    Université Paris-Saclay

86. Senjuti Bhattacharya

    Eötvös Loránd University · European Organization for Nuclear Research

    Affiliation as printed

    Eotvos Lorand University

    European Organization for Nuclear Research (CERN)

87. M. S. Bieker

    University of Bonn

    Affiliation as printed

    Universität Bonn—Helmholtz-Institut für Strahlen und Kernphysik

88. N. V. Biesuz

    Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara

    Affiliation as printed

    INFN Sezione di Ferrara

89. Alice Biolchini

    National Institute for Subatomic Physics

    Affiliation as printed

    Nikhef National Institute for Subatomic Physics

90. M. Birch

    Imperial College London

    Affiliation as printed

    Imperial College London

91. F. C. R. Bishop

    Université Savoie Mont Blanc

    Affiliation as printed

    Université Savoie Mont Blanc

92. A. Bitadze

    University of Manchester

    Affiliation as printed

    University of Manchester

93. A. Bizzeti

    Istituto Nazionale di Fisica Nucleare, Sezione di Firenze

    Affiliation as printed

    INFN Sezione di Firenze

94. T. Blake

    University of Warwick

    Affiliation as printed

    University of Warwick

95. F. Blanc
    Affiliation as printed

    Institute of Physics

96. J. E. Blank

    TU Dortmund University

    Affiliation as printed

    Technische Universität Dortmund

97. Steven Roy Blusk

    Syracuse University

    Affiliation as printed

    Syracuse University

98. J. A. Boelhauve

    TU Dortmund University

    Affiliation as printed

    Technische Universität Dortmund

99. O. Boente García

    European Organization for Nuclear Research

    Affiliation as printed

    European Organization for Nuclear Research (CERN)