Please use this identifier to cite or link to this item:
https://hdl.handle.net/10316/107103
Title: | Search for top-quark decays t → Hq with 36 fb−1 of pp collision data at √s = 13 TeV with the ATLAS detector | Authors: | Santos, S. P. Amor dos Fiolhais, M. C. N. Galhardo, B. Veloso, F. Wolters, H. ATLAS Collaboration |
Keywords: | Hadron-Hadron scattering (experiments); Rare decay; Top physics | Issue Date: | 2019 | Publisher: | Springer Nature | Serial title, monograph or event: | Journal of High Energy Physics | Volume: | 2019 | Issue: | 5 | Place of publication or event: | 123 | Abstract: | 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.[Figure not available: see fulltext.] | URI: | https://hdl.handle.net/10316/107103 | DOI: | 10.1007/JHEP05(2019)123 | Rights: | openAccess |
Appears in Collections: | FCTUC Física - Artigos em Revistas Internacionais |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
Search-for-topquark-decays-t--Hq-with-36-fbsup1sup-of-pp-collision-data-at-s--13-TeV-with-the-ATLAS-detectorJournal-of-High-Energy-Physics.pdf | 1.53 MB | Adobe PDF | View/Open |
This item is licensed under a Creative Commons License