Observation of the charmless purely baryonic decay $$ {\Lambda}_b^0\to \Lambda p\overline{p} $$

Journal of High Energy Physics, vol. 2026

Abstract

A bstract A search for the charmless purely baryonic decay $$ {\Lambda}_b^0\to \Lambda p\overline{p} $$ Λ b 0 → Λ p p ¯ is performed using proton-proton collision data recorded by the LHCb experiment at a centre-of-mass energy of $$ \sqrt{s}=13 $$ s = 13 TeV and corresponding to an integrated luminosity of 6 . 0 fb − 1 . The signal decay is observed with a significance of 5.1 standard deviations. Its branching fraction is measured for the first time, relative to that of the topologically similar decay $$ {\Lambda}_b^0\to \Lambda {K}^{+}{K}^{-} $$ Λ b 0 → Λ K + K − . Contributions from intermediate charmonium resonances decaying to the $$ p\overline{p} $$ p p ¯ and K + K − final states are explicitly excluded with a requirement on the invariant mass of the companion hadron system, $$ m\left(h\overline{h}\right)<2.85 $$ m h h ¯ < 2.85 GeV, where h stands for a proton or a charged kaon. The relative branching fraction is found to be $$ \frac{\mathcal{B}\left({\Lambda}_b^0\to \Lambda p\overline{p}\right)}{\mathcal{B}\left({\Lambda}_b^0\to \Lambda {K}^{+}{K}^{-}\right)}=\left(5.1\pm {1.3}_{\left(\mathrm{stat}\right)}\pm {0.3}_{\left(\mathrm{syst}\right)}\right)\times {10}^{-2}. $$ B Λ b 0 → Λ p p ¯ B Λ b 0 → Λ K + K − = 5.1 ± 1.3 stat ± 0.3 syst × 10 − 2 .

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. 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

61. W. Barter

    University of Edinburgh

    Affiliation as printed

    University of Edinburgh

62. W. Barter

    Syracuse University

    Affiliation as printed

    Syracuse University

63. B. Batsukh

    AGH University of Krakow

    Affiliation as printed

    AGH — University of Krakow, Faculty of Physics and Applied Computer Science

64. B. Batsukh
    Affiliation as printed

    Institute of Physics and Technology

65. 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

66. Ali Bavarchee

    Eötvös Loránd University

    Affiliation as printed

    Eotvos Lorand University

67. A. Bay

    École Polytechnique Fédérale de Lausanne

    Affiliation as printed

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

68. A. Beck

    Massachusetts Institute of Technology

    Affiliation as printed

    Massachusetts Institute of Technology

69. M. Becker

    TU Dortmund University

    Affiliation as printed

    Technische Universität Dortmund

70. F. Bedeschi

    Istituto Nazionale di Fisica Nucleare, Sezione di Pisa

    Affiliation as printed

    INFN Sezione di Pisa

71. I. Bediaga

    Centro Brasileiro de Pesquisas Físicas

    Affiliation as printed

    Centro Brasileiro de Pesquisas Físicas (CBPF)

72. Noah Albin Behling

    TU Dortmund University

    Affiliation as printed

    Technische Universität Dortmund

73. S. Belin

    Universidade de Santiago de Compostela

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    Universidade de Santiago de Compostela

74. Alberto Bellavista

    Istituto Nazionale di Fisica Nucleare, Sezione di Bologna

    Affiliation as printed

    INFN Sezione di Bologna

75. I. Belov

    Istituto Nazionale di Fisica Nucleare, Sezione di Genova

    Affiliation as printed

    INFN Sezione di Genova

76. I. Belyaev

    Istituto Nazionale di Fisica Nucleare, Sezione di Roma I

    Affiliation as printed

    INFN Sezione di Roma La Sapienza

77. 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

78. G. Bencivenni

    Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati

    Affiliation as printed

    INFN Laboratori Nazionali di Frascati

79. R. Bernet

    University of Zurich

    Affiliation as printed

    Universität Zürich

80. A. Bertolin

    Istituto Nazionale di Fisica Nucleare, Sezione di Padova

    Affiliation as printed

    INFN Sezione di Padova

81. F. Betti

    University of Edinburgh

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    University of Edinburgh

82. J. Bex

    University of Cambridge

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    University of Cambridge

83. Oleg Bezshyyko

    Taras Shevchenko National University of Kyiv

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    Taras Schevchenko University of Kyiv, Faculty of Physics

84. Senjuti Bhattacharya

    Eötvös Loránd University

    Affiliation as printed

    Eotvos Lorand University

85. M. S. Bieker

    University of Bonn

    Affiliation as printed

    Universität Bonn — Helmholtz-Institut für Strahlen und Kernphysik

86. N. V. Biesuz

    Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara

    Affiliation as printed

    INFN Sezione di Ferrara

87. Alice Biolchini

    National Institute for Subatomic Physics

    Affiliation as printed

    Nikhef National Institute for Subatomic Physics

88. M. Birch

    Imperial College London

    Affiliation as printed

    Imperial College London

89. 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

90. A. Bitadze

    University of Manchester

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    University of Manchester

91. A. Bizzeti

    Istituto Nazionale di Fisica Nucleare, Sezione di Firenze

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    INFN Sezione di Firenze

92. T. Blake

    University of Warwick

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    University of Warwick

93. F. Blanc

    École Polytechnique Fédérale de Lausanne

    Affiliation as printed

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

94. J. E. Blank

    TU Dortmund University

    Affiliation as printed

    Technische Universität Dortmund

95. Steven Roy Blusk

    Syracuse University

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    Syracuse University

96. J. A. Boelhauve

    TU Dortmund University

    Affiliation as printed

    Technische Universität Dortmund

97. O. Boente García

    European Organization for Nuclear Research

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    European Organization for Nuclear Research (CERN)

98. T. Boettcher

    Indiana University

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    Indiana University

99. A. Bohare

    University of Edinburgh

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    University of Edinburgh