Search for new physics using effective field theory in 13 TeV $pp$ collision events that contain a top quark pair and a boosted $Z$ or Higgs boson

Institutional Research Information System University of Turin (University of Turin)

Abstract

A data sample containing top quark pairs (tt over bar ) produced in association with a Lorentz-boosted Z or Higgs boson is used to search for signs of new physics using effective field theory. The data correspond to an integrated luminosity of 138 fb-1 of proton-proton collisions produced at a center-of-mass energy of 13 TeV at the LHC and collected by the CMS experiment. Selected events contain a single lepton and hadronic jets, including two identified with the decay of bottom quarks, plus an additional large-radius jet with high transverse momentum identified as a Z or Higgs boson decaying to a bottom quark pair. Machine learning techniques are employed to discriminate between tt over bar Z or tt over bar H events and events from background processes, which are dominated by tt over bar + jets production. No indications of new physics are observed. The signal strengths of boosted tt over bar Z and tt over bar H production are measured, and upper limits are placed on the tt over bar Z and tt over bar H differential cross sections as functions of the Z or Higgs boson transverse momentum. The effects of new physics are probed using a framework in which the standard model is considered to be the low-energy effective field theory of a higher energy scale theory. Eight possible dimension-six operators are added to the standard model Lagrangian, and their corresponding coefficients are constrained via fits to the data.

Authors 100

1. A. R. Tumasyan

   A. Alikhanyan National Laboratory

   Affiliation as printed

   Yerevan Physics Institute, Yerevan, Armenia

2. W. Adam

   Institute of High Energy Physics

   Affiliation as printed

   Institut für Hochenergiephysik, Vienna, Austria

3. J. W. Andrejkovic

   Institute of High Energy Physics

   Affiliation as printed

   Institut für Hochenergiephysik, Vienna, Austria

4. T. Bergauer

   Institute of High Energy Physics

   Affiliation as printed

   Institut für Hochenergiephysik, Vienna, Austria

5. S. Chatterjee

   Institute of High Energy Physics

   Affiliation as printed

   Institut für Hochenergiephysik, Vienna, Austria

6. K. Damanakis

   Institute of High Energy Physics

   Affiliation as printed

   Institut für Hochenergiephysik, Vienna, Austria

7. M. Dragicevic

   Institute of High Energy Physics

   Affiliation as printed

   Institut für Hochenergiephysik, Vienna, Austria

8. A. Escalante Del Valle

   Institute of High Energy Physics

   Affiliation as printed

   Institut für Hochenergiephysik, Vienna, Austria

9. Priya Sajid Hussain

   Institute of High Energy Physics

   Affiliation as printed

   Institut für Hochenergiephysik, Vienna, Austria

10. M. Jeitler

    Institute of High Energy Physics

    Affiliation as printed

    Institut für Hochenergiephysik, Vienna, Austria

11. N. Krammer

    Institute of High Energy Physics

    Affiliation as printed

    Institut für Hochenergiephysik, Vienna, Austria

12. L. Lechner

    Institute of High Energy Physics

    Affiliation as printed

    Institut für Hochenergiephysik, Vienna, Austria

13. D. Liko

    Institute of High Energy Physics

    Affiliation as printed

    Institut für Hochenergiephysik, Vienna, Austria

14. I. Mikulec

    Institute of High Energy Physics

    Affiliation as printed

    Institut für Hochenergiephysik, Vienna, Austria

15. P. Paulitsch

    Institute of High Energy Physics

    Affiliation as printed

    Institut für Hochenergiephysik, Vienna, Austria

16. F. M. Pitters

    Institute of High Energy Physics

    Affiliation as printed

    Institut für Hochenergiephysik, Vienna, Austria

17. J. Schieck

    Institute of High Energy Physics

    Affiliation as printed

    Institut für Hochenergiephysik, Vienna, Austria

18. R. Schoefbeck

    Institute of High Energy Physics

    Affiliation as printed

    Institut für Hochenergiephysik, Vienna, Austria

19. D. Schwarz

    Institute of High Energy Physics

    Affiliation as printed

    Institut für Hochenergiephysik, Vienna, Austria

20. S. Templ

    Institute of High Energy Physics

    Affiliation as printed

    Institut für Hochenergiephysik, Vienna, Austria

21. W. Waltenberger

    Institute of High Energy Physics

    Affiliation as printed

    Institut für Hochenergiephysik, Vienna, Austria

22. C.-E. Wulz

    Institute of High Energy Physics

    Affiliation as printed

    Institut für Hochenergiephysik, Vienna, Austria

23. M. R. Darwish

    University of Antwerp

    Affiliation as printed

    Universiteit Antwerpen, Antwerpen, Belgium

24. X. Janssen

    University of Antwerp

    Affiliation as printed

    Universiteit Antwerpen, Antwerpen, Belgium

25. T. Kello

    University of Antwerp

    Affiliation as printed

    Universiteit Antwerpen, Antwerpen, Belgium

26. H. Rejeb Sfar

    University of Antwerp

    Affiliation as printed

    Universiteit Antwerpen, Antwerpen, Belgium

27. P. Van Mechelen

    University of Antwerp

    Affiliation as printed

    Universiteit Antwerpen, Antwerpen, Belgium

28. E. S. Bols

    Vrije Universiteit Brussel

    Affiliation as printed

    Vrije Universiteit Brussel, Brussel, Belgium

29. J. D’Hondt

    Vrije Universiteit Brussel

    Affiliation as printed

    Vrije Universiteit Brussel, Brussel, Belgium

30. A. De Moor

    Vrije Universiteit Brussel

    Affiliation as printed

    Vrije Universiteit Brussel, Brussel, Belgium

31. M. Delcourt

    Vrije Universiteit Brussel

    Affiliation as printed

    Vrije Universiteit Brussel, Brussel, Belgium

32. H. El Faham

    Vrije Universiteit Brussel

    Affiliation as printed

    Vrije Universiteit Brussel, Brussel, Belgium

33. S. Lowette

    Vrije Universiteit Brussel

    Affiliation as printed

    Vrije Universiteit Brussel, Brussel, Belgium

34. S. Moortgat

    Vrije Universiteit Brussel

    Affiliation as printed

    Vrije Universiteit Brussel, Brussel, Belgium

35. A. Morton

    Vrije Universiteit Brussel

    Affiliation as printed

    Vrije Universiteit Brussel, Brussel, Belgium

36. D. Müller

    Vrije Universiteit Brussel

    Affiliation as printed

    Vrije Universiteit Brussel, Brussel, Belgium

37. Abanti Ranadhir Sahasransu

    Vrije Universiteit Brussel

    Affiliation as printed

    Vrije Universiteit Brussel, Brussel, Belgium

38. S. Tavernier

    Vrije Universiteit Brussel

    Affiliation as printed

    Vrije Universiteit Brussel, Brussel, Belgium

39. W. Van Doninck

    Vrije Universiteit Brussel

    Affiliation as printed

    Vrije Universiteit Brussel, Brussel, Belgium

40. David Vannerom

    Vrije Universiteit Brussel

    Affiliation as printed

    Vrije Universiteit Brussel, Brussel, Belgium

41. B. Clerbaux

    Université Libre de Bruxelles

    Affiliation as printed

    Université Libre de Bruxelles, Bruxelles, Belgium

42. G. De Lentdecker

    Université Libre de Bruxelles

    Affiliation as printed

    Université Libre de Bruxelles, Bruxelles, Belgium

43. L. Favart

    Université Libre de Bruxelles

    Affiliation as printed

    Université Libre de Bruxelles, Bruxelles, Belgium

44. D. Hohov

    Université Libre de Bruxelles

    Affiliation as printed

    Université Libre de Bruxelles, Bruxelles, Belgium

45. J. Jaramillo

    Université Libre de Bruxelles

    Affiliation as printed

    Université Libre de Bruxelles, Bruxelles, Belgium

46. Kyeongpil Lee

    Université Libre de Bruxelles

    Affiliation as printed

    Université Libre de Bruxelles, Bruxelles, Belgium

47. M. Mahdavikhorrami

    Université Libre de Bruxelles

    Affiliation as printed

    Université Libre de Bruxelles, Bruxelles, Belgium

48. Inna Makarenko

    Université Libre de Bruxelles

    Affiliation as printed

    Université Libre de Bruxelles, Bruxelles, Belgium

49. Andrea Malara

    Université Libre de Bruxelles

    Affiliation as printed

    Université Libre de Bruxelles, Bruxelles, Belgium

50. S. Paredes

    Université Libre de Bruxelles

    Affiliation as printed

    Université Libre de Bruxelles, Bruxelles, Belgium

51. L. Pétré

    Université Libre de Bruxelles

    Affiliation as printed

    Université Libre de Bruxelles, Bruxelles, Belgium

52. N. Postiau

    Université Libre de Bruxelles

    Affiliation as printed

    Université Libre de Bruxelles, Bruxelles, Belgium

53. E. Starling

    Université Libre de Bruxelles

    Affiliation as printed

    Université Libre de Bruxelles, Bruxelles, Belgium

54. L. Thomas

    Université Libre de Bruxelles

    Affiliation as printed

    Université Libre de Bruxelles, Bruxelles, Belgium

55. M. Vanden Bemden

    Université Libre de Bruxelles

    Affiliation as printed

    Université Libre de Bruxelles, Bruxelles, Belgium

56. C. Vander Velde

    Université Libre de Bruxelles

    Affiliation as printed

    Université Libre de Bruxelles, Bruxelles, Belgium

57. Dobur, D.

    Université Libre de Bruxelles

    Affiliation as printed

    Université Libre de Bruxelles, Bruxelles, Belgium

58. D. Dobur

    Ghent University

    Affiliation as printed

    Ghent University, Ghent, Belgium

59. J. Knolle

    Ghent University

    Affiliation as printed

    Ghent University, Ghent, Belgium

60. L. Lambrecht

    Ghent University

    Affiliation as printed

    Ghent University, Ghent, Belgium

61. G. Mestdach

    Ghent University

    Affiliation as printed

    Ghent University, Ghent, Belgium

62. M. Niedziela

    Ghent University

    Affiliation as printed

    Ghent University, Ghent, Belgium

63. C. Rendón

    Ghent University

    Affiliation as printed

    Ghent University, Ghent, Belgium

64. C. Roskas

    Ghent University

    Affiliation as printed

    Ghent University, Ghent, Belgium

65. A. Samalan

    Ghent University

    Affiliation as printed

    Ghent University, Ghent, Belgium

66. K. Skovpen

    Ghent University

    Affiliation as printed

    Ghent University, Ghent, Belgium

67. M. Tytgat

    Ghent University

    Affiliation as printed

    Ghent University, Ghent, Belgium

68. N. Van Den Bossche

    Ghent University

    Affiliation as printed

    Ghent University, Ghent, Belgium

69. B. Vermassen

    Ghent University

    Affiliation as printed

    Ghent University, Ghent, Belgium

70. L. Wezenbeek

    Ghent University

    Affiliation as printed

    Ghent University, Ghent, Belgium

71. A. Benecke

    UCLouvain

    Affiliation as printed

    Université Catholique de Louvain, Louvain-la-Neuve, Belgium

72. G. Bruno

    UCLouvain

    Affiliation as printed

    Université Catholique de Louvain, Louvain-la-Neuve, Belgium

73. F. Bury

    UCLouvain

    Affiliation as printed

    Université Catholique de Louvain, Louvain-la-Neuve, Belgium

74. C. Caputo

    UCLouvain

    Affiliation as printed

    Université Catholique de Louvain, Louvain-la-Neuve, Belgium

75. P. David

    UCLouvain

    Affiliation as printed

    Université Catholique de Louvain, Louvain-la-Neuve, Belgium

76. C. Delaere

    UCLouvain

    Affiliation as printed

    Université Catholique de Louvain, Louvain-la-Neuve, Belgium

77. I. S. Donertas

    UCLouvain

    Affiliation as printed

    Université Catholique de Louvain, Louvain-la-Neuve, Belgium

78. A. Giammanco

    UCLouvain

    Affiliation as printed

    Université Catholique de Louvain, Louvain-la-Neuve, Belgium

79. K. Jaffel

    UCLouvain

    Affiliation as printed

    Université Catholique de Louvain, Louvain-la-Neuve, Belgium

80. Sa. Jain

    UCLouvain

    Affiliation as printed

    Université Catholique de Louvain, Louvain-la-Neuve, Belgium

81. V. Lemaitre

    UCLouvain

    Affiliation as printed

    Université Catholique de Louvain, Louvain-la-Neuve, Belgium

82. K. Mondal

    UCLouvain

    Affiliation as printed

    Université Catholique de Louvain, Louvain-la-Neuve, Belgium

83. J. Prisciandaro

    UCLouvain

    Affiliation as printed

    Université Catholique de Louvain, Louvain-la-Neuve, Belgium

84. A. Taliercio

    UCLouvain

    Affiliation as printed

    Université Catholique de Louvain, Louvain-la-Neuve, Belgium

85. T. T. Tran

    UCLouvain

    Affiliation as printed

    Université Catholique de Louvain, Louvain-la-Neuve, Belgium

86. P. Vischia

    UCLouvain

    Affiliation as printed

    Université Catholique de Louvain, Louvain-la-Neuve, Belgium

87. S. Wertz

    UCLouvain

    Affiliation as printed

    Université Catholique de Louvain, Louvain-la-Neuve, Belgium

88. G. A. Alves

    Centro Brasileiro de Pesquisas Físicas

    Affiliation as printed

    Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brazil

89. E. Coelho

    Centro Brasileiro de Pesquisas Físicas

    Affiliation as printed

    Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brazil

90. C. Hensel

    Centro Brasileiro de Pesquisas Físicas

    Affiliation as printed

    Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brazil

91. A. Moraes

    Centro Brasileiro de Pesquisas Físicas

    Affiliation as printed

    Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brazil

92. P. Rebello Teles

    Centro Brasileiro de Pesquisas Físicas

    Affiliation as printed

    Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brazil

93. W. L. Aldá Júnior

    Universidade do Estado do Rio de Janeiro

    Affiliation as printed

    Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil

94. M. Alves Gallo Pereira

    Universidade do Estado do Rio de Janeiro

    Affiliation as printed

    Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil

95. M. Barroso Ferreira Filho

    Universidade do Estado do Rio de Janeiro

    Affiliation as printed

    Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil

96. H. Brandao Malbouisson

    Universidade do Estado do Rio de Janeiro

    Affiliation as printed

    Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil

97. W. Carvalho

    Universidade do Estado do Rio de Janeiro

    Affiliation as printed

    Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil

98. J. Chinellato

    Universidade do Estado do Rio de Janeiro

    Affiliation as printed

    Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil

99. E. M. Da Costa

    Universidade do Estado do Rio de Janeiro

    Affiliation as printed

    Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil

100. G. G. Da Silveira

     Universidade do Estado do Rio de Janeiro

     Affiliation as printed

     Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil