Miucci, Antonio; Merlassino, Claudia; Haug, Sigve; Weber, Michael; Anders, John Kenneth; Beck, Hans Peter; Ereditato, Antonio; Rimoldi, Marco; Weston, Thomas Daniel (2019). Search for top-quark decays t → Hq with 36 fb⁻¹ of pp collision data at √s=13 TeV with the ATLAS detector. Journal of High Energy Physics, 2019(5) Springer 10.1007/JHEP05(2019)123
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Aaboud2019_Article_SearchForTop-quarkDecaysTHqWiT.pdf - Published Version Available under License Creative Commons: Attribution (CC-BY). Download (1MB) | Preview |
A search for flavour-changing neutral current decays of a top quark into an up-type quark (q = u, c) and the Standard Model Higgs boson, t → Hq, is presented. The search is based on a dataset of pp collisions at √s = 13 TeV recorded in 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider and corresponding to an integrated luminosity of 36.1 fb−1. Two complementary analyses are performed to search for top-quark pair events in which one top quark decays into Wb and the other top quark decays into Hq, and target the H→bb¯¯ and H → τ+τ− decay modes, respectively. The high multiplicity of b-quark jets, or the presence of hadronically decaying τ-leptons, is exploited in the two analyses respectively. Multivariate techniques are used to separate the signal from the background, which is dominated by top-quark pair production. No significant excess of events above the background expectation is found, and 95% CL upper limits on the t → Hq branching ratios are derived. The combination of these searches with ATLAS searches in diphoton and multilepton final states yields observed (expected) 95% CL upper limits on the t → Hc and t → Hu branching ratios of 1.1 × 10−3 (8.3 × 10−4) and 1.2 × 10−3 (8.3 × 10−4), respectively. The corresponding combined observed (expected) upper limits on the |λtcH| and |λtuH| couplings are 0.064 (0.055) and 0.066 (0.055), respectively.
Item Type: |
Journal Article (Original Article) |
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Division/Institute: |
10 Strategic Research Centers > Albert Einstein Center for Fundamental Physics (AEC) 08 Faculty of Science > Physics Institute > Laboratory for High Energy Physics (LHEP) |
UniBE Contributor: |
Miucci, Antonio, Merlassino, Claudia, Haug, Sigve, Weber, Michele, Anders, John Kenneth, Beck, Hans Peter, Ereditato, Antonio, Rimoldi, Marco, Weston, Thomas Daniel |
Subjects: |
500 Science > 530 Physics |
ISSN: |
1029-8479 |
Publisher: |
Springer |
Language: |
English |
Submitter: |
BORIS Import LHEP |
Date Deposited: |
18 Jun 2020 10:26 |
Last Modified: |
23 Jan 2024 06:05 |
Publisher DOI: |
10.1007/JHEP05(2019)123 |
Additional Information: |
Kollaboration - Es sind nur die Berner Autoren namentlich erwaehnt; ATLAS collaboration |
BORIS DOI: |
10.7892/boris.143610 |
URI: |
https://boris.unibe.ch/id/eprint/143610 |
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