Angular analysis of the B+ → π+μ+μ− decay

Journal of High Energy Physics, vol. 2026

Abstract

A bstract This paper presents the first measurement of the forward-backward asymmetry, A FB , and the flat term, F H , that parameterise the angular distribution of the B + → π + μ + μ − decay. The proton-proton collision dataset used in the analysis corresponds to an integrated luminosity of 9 fb − 1 , collected with the LHCb experiment between 2011 and 2018. The analysis is performed in two intervals of dimuon mass squared, one above and one below the region containing the J/ψ and ψ (2 S ) narrow charmonium resonances. The Standard Model predictions lie within the obtained 68% confidence level interval in the high-mass and within the 99% interval in the low-mass region.

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

    Affiliation as printed

    National Center for Nuclear Research (NCBJ)

    Uppsala University

11. C. Agapopoulou

    Centre National de la Recherche Scientifique · Université Paris-Saclay · Institut National de Physique Nucléaire et de Physique des Particules · Laboratoire de Physique des 2 Infinis Irène Joliot-Curie

    Affiliation as printed

    Université Paris-Saclay, CNRS/IN2P3, IJCLab

12. C. Aidala

    University of Michigan

    Affiliation as printed

    University of Michigan

13. S. Akar

    Centre National de la Recherche Scientifique · Université Clermont Auvergne · Institut National de Physique Nucléaire et de Physique des Particules

    Affiliation as printed

    Université Clermont Auvergne, CNRS/IN2P3, LPC

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

    Vilnius University

    Affiliation as printed

    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

    Centre National de la Recherche Scientifique · Université Paris-Saclay · Institut National de Physique Nucléaire et de Physique des Particules · Laboratoire de Physique des 2 Infinis Irène Joliot-Curie

    Affiliation as printed

    Université Paris-Saclay, CNRS/IN2P3, IJCLab

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

    Commissariat à l'Énergie Atomique et aux Énergies Alternatives · Université Paris-Saclay · CEA Paris-Saclay - Etablissement de Saclay · Institut de Recherche sur les Lois Fondamentales de l'Univers

    Affiliation as printed

    Université Paris-Saclay, Centre d’Etudes de Saclay (CEA), IRFU

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

    Centre National de la Recherche Scientifique · Aix-Marseille Université · Centre de physique des particules de Marseille · Institut National de Physique Nucléaire et de Physique des Particules

    Affiliation as printed

    Aix Marseille Univ, CNRS/IN2P3, CPPM

38. R. Ataíde Da Silva

    École Polytechnique Fédérale de Lausanne

    Affiliation as printed

    Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL)

39. M. Atzeni

    Massachusetts Institute of Technology

    Affiliation as printed

    Massachusetts Institute of Technology

40. B. Audurier

    Commissariat à l'Énergie Atomique et aux Énergies Alternatives · Université Paris-Saclay · CEA Paris-Saclay - Etablissement de Saclay · Institut de Recherche sur les Lois Fondamentales de l'Univers

    Affiliation as printed

    Université Paris-Saclay, Centre d’Etudes de Saclay (CEA), IRFU

41. Juliette Authier

    Centre National de la Recherche Scientifique · École Polytechnique · Institut National de Physique Nucléaire et de Physique des Particules · Institut Polytechnique de Paris · Laboratoire Leprince-Ringuet

    Affiliation as printed

    Laboratoire Leprince-Ringuet, CNRS/IN2P3, Ecole Polytechnique, Institut Polytechnique de Paris

42. D. Bacher

    University of Oxford

    Affiliation as printed

    University of Oxford

43. I. Bachiller

    École Polytechnique Fédérale de Lausanne

    Affiliation as printed

    Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL)

44. S. Bachmann

    Heidelberg University

    Affiliation as printed

    Ruprecht-Karls-Universität Heidelberg

45. Marie Bachmayer

    École Polytechnique Fédérale de Lausanne

    Affiliation as printed

    Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL)

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

    Centre National de la Recherche Scientifique · École Polytechnique · Institut National de Physique Nucléaire et de Physique des Particules · Institut Polytechnique de Paris · Laboratoire Leprince-Ringuet

    Affiliation as printed

    Laboratoire Leprince-Ringuet, CNRS/IN2P3, Ecole Polytechnique, Institut Polytechnique de Paris

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

    Ruhr University Bochum

    Affiliation as printed

    Ruhr Universitaet Bochum, Fakultaet f. Physik und Astronomie

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 · Commissariat à l'Énergie Atomique et aux Énergies Alternatives · Université Paris-Saclay · CEA Paris-Saclay - Etablissement de Saclay · Institut de Recherche sur les Lois Fondamentales de l'Univers

    Affiliation as printed

    Universidade de Santiago de Compostela

    Université Paris-Saclay, Centre d’Etudes de Saclay (CEA), IRFU

56. M. Barbetti

    Istituto Nazionale di Fisica Nucleare, Sezione di Firenze

    Affiliation as printed

    INFN Sezione di Firenze

57. I. R. Barbosa

    Pontifícia Universidade Católica do Rio de Janeiro

    Affiliation as printed

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

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

    Centre National de la Recherche Scientifique · Université Paris-Saclay · Institut National de Physique Nucléaire et de Physique des Particules · Laboratoire de Physique des 2 Infinis Irène Joliot-Curie

    Affiliation as printed

    Université Paris-Saclay, CNRS/IN2P3, IJCLab

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, Faculty of Physics and Applied Computer Science

65. B. Batsukh
    Affiliation as printed

    Institute of Physics and Technology

66. Piera Battista

    Centre National de la Recherche Scientifique · Université Paris-Saclay · Institut National de Physique Nucléaire et de Physique des Particules · Laboratoire de Physique des 2 Infinis Irène Joliot-Curie

    Affiliation as printed

    Université Paris-Saclay, CNRS/IN2P3, IJCLab

67. Ali Bavarchee

    Eötvös Loránd University

    Affiliation as printed

    Eotvos Lorand University

68. A. Bay

    École Polytechnique Fédérale de Lausanne

    Affiliation as printed

    Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL)

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. E. Ben-Haim

    Centre National de la Recherche Scientifique · Sorbonne Université · Laboratoire de Physique Nucléaire et de Hautes Énergies · Institut National de Physique Nucléaire et de Physique des Particules

    Affiliation as printed

    Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), Sorbonne Université, CNRS/IN2P3

79. G. Bencivenni

    Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati

    Affiliation as printed

    INFN Laboratori Nazionali di Frascati

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

    Affiliation as printed

    Taras Schevchenko University of Kyiv, Faculty of Physics

86. Senjuti Bhattacharya

    Eötvös Loránd University

    Affiliation as printed

    Eotvos Lorand University

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

    Centre National de la Recherche Scientifique · Laboratoire d’Annecy de Physique des Particules · Institut National de Physique Nucléaire et de Physique des Particules · Université Savoie Mont Blanc

    Affiliation as printed

    Université Savoie Mont Blanc, CNRS, IN2P3-LAPP

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

    École Polytechnique Fédérale de Lausanne

    Affiliation as printed

    Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL)

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)