Measurement of the production cross-section of a single top quark in association with a Z boson in proton–proton collisions at 13 TeV with the ATLAS detector

0500191 - FZÚ 2019 RIV NL eng J - Journal Article
Aaboud, M. - Aad, G. - Abbott, B. - Chudoba, Jiří - Hejbal, Jiří - Hladík, Ondřej - Jakoubek, Tomáš - Kepka, Oldřich - Kroll, Jiří - Kupčo, Alexander - Lokajíček, Miloš - Lysák, Roman - Marčišovský, Michal - Mikeštíková, Marcela - Němeček, Stanislav - Penc, Ondřej - Šícho, Petr - Staroba, Pavel - Svatoš, Michal - Taševský, Marek … Total 2900 authors
Measurement of the production cross-section of a single top quark in association with a Z boson in proton–proton collisions at 13 TeV with the ATLAS detector.
Physics Letters. B. Roč. 780, May (2018), s. 557-577. ISSN 0370-2693. E-ISSN 1873-2445
R&D Projects: GA MŠMT(CZ) LTT17018
Institutional support: RVO:68378271
Keywords : CERN LHC Coll * final state: ((n)jet 3lepton) * jet: bottom * bottom: particle identification * data analysis method * experimental results * 13000 GeV-cms
OECD category: Particles and field physics
Impact factor: 4.162, year: 2018

The production of a top quark in association with a Z boson is investigated. The proton–proton collision data collected by the ATLAS experiment at the LHC in 2015 and 2016 at a centre-of-mass energy of s=13TeV are used, corresponding to an integrated luminosity of 36.1fb−1 . Events containing three identified leptons (electrons and/or muons) and two jets, one of which is identified as a b -quark jet are selected. The major backgrounds are diboson, tt¯ and Z+jets production. A neural network is used to improve the background rejection and extract the signal. The resulting significance is 4.2 σ in the data and the expected significance is 5.4 σ . The measured cross-section for tZq production is 600±170(stat.)±140(syst.)fb .

Permanent Link: http://hdl.handle.net/11104/0292309