CP Properties of Higgs Boson Interactions with Top Quarks in the (tt)over-barH and tH Processes Using H -> gamma gamma with the ATLAS Detector



Aad, G, Abbott, B, Abbott, DC, Abud, A Abed, Abeling, K, Abhayasinghe, DK, Abidi, SH, AbouZeid, OS, Abraham, NL, Abramowicz, H
et al (show 2939 more authors) (2020) CP Properties of Higgs Boson Interactions with Top Quarks in the (tt)over-barH and tH Processes Using H -> gamma gamma with the ATLAS Detector. PHYSICAL REVIEW LETTERS, 125 (6). 061802-.

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Abstract

A study of the charge conjugation and parity (CP) properties of the interaction between the Higgs boson and top quarks is presented. Higgs bosons are identified via the diphoton decay channel (H→γγ), and their production in association with a top quark pair (tt[over ¯]H) or single top quark (tH) is studied. The analysis uses 139  fb^{-1} of proton-proton collision data recorded at a center-of-mass energy of sqrt[s]=13  TeV with the ATLAS detector at the Large Hadron Collider. Assuming a CP-even coupling, the tt[over ¯]H process is observed with a significance of 5.2 standard deviations. The measured cross section times H→γγ branching ratio is 1.64_{-0.36}^{+0.38}(stat)_{-0.14}^{+0.17}(sys)  fb, and the measured rate for tt[over ¯]H is 1.43_{-0.31}^{+0.33}(stat)_{-0.15}^{+0.21}(sys) times the Standard Model expectation. The tH production process is not observed and an upper limit on its rate of 12 times the Standard Model expectation is set. A CP-mixing angle greater (less) than 43 (-43)° is excluded at 95% confidence level.

Item Type: Article
Additional Information: 29 pages in total, author list starting page 13, 3 figures, no tables, published in Phys. Rev. Lett. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HIGG-2019-01/
Uncontrolled Keywords: ATLAS Collaboration
Depositing User: Symplectic Admin
Date Deposited: 24 Aug 2020 07:19
Last Modified: 18 Mar 2024 04:10
DOI: 10.1103/PhysRevLett.125.061802
Open Access URL: https://journals.aps.org/prl/abstract/10.1103/Phys...
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URI: https://livrepository.liverpool.ac.uk/id/eprint/3098584