Ústav technické a experimentální fyziky Institute of Experimental and Applied Physics

Evidence for single top-quark production in the s-channel in proton-proton collisions at root s=8 TeV with the ATLAS detector using the Matrix Element Method

NázevTitle
Evidence for single top-quark production in the s-channel in proton-proton collisions at root s=8 TeV with the ATLAS detector using the Matrix Element MethodEvidence for single top-quark production in the s-channel in proton-proton collisions at root s=8 TeV with the ATLAS detector using the Matrix Element Method
Druh výsledkuResult type
Článek v časopiseJournal article
AutořiAuthors
G. Aad, B. Abbott, J. Abdallah, O. Abdinov, K. Augsten, D. Caforio, P. Gallus, J. Guenther, Z. Hubáček, J. Jakůbek, Z. Kohout, M. Myška, S. Pospíšil, F. Seifert, V. Šimák, T. Slavíček, K. Smolek, M. Solar, J. Šolc, A. Sopczak, B. Sopko, V. Sopko, M. Suk, V. Vacek, M. Vlasak, P. Vokáč, Z. Vykydal, M. Zeman
DOIDOI
10.1016/j.physletb.2016.03.017
Časopis / citaceJournal / citation
Physics Letters B. 2016, 756 228-246. ISSN 0370-2693.
RokYear
2016
JazykLanguage
eng
WoSWoS
000373569200035
ScopusScopus
2-s2.0-85042024827
RIVRIV
RIV/68407700:21220/16:00309040!RIV17-MSM-21220___
ProjektProject
CERN-CZ - Výzkumná infrastruktura pro experimenty v CERN - LM2015058 (2016–2019)CERN-CZ - Výzkumná infrastruktura pro experimenty v CERN - LM2015058 (2016–2019); Zkoumání mikrosvěta s využitím infrastruktury CERNInvestigation of the Microworld using the CERN Infrastructure

AbstraktAbstract

This Letter presents evidence for single top-quark production in the s-channel using proton-proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS detector at the CERN Large Hadron Collider. The analysis is performed on events containing one isolated electron or muon, large missing transverse momentum and exactly two b-tagged jets in the final state. The analysed data set corresponds to an integrated luminosity of 20.3 fb(-1). The signal is extracted using a maximum-likelihood fit of a discriminant which is based on the matrix element method and optimized in order to separate single-top-quark s-channel events from the main background contributions, which are top-quark pair production and W boson production in association with heavy-flavour jets. The measurement leads to an observed signal significance of 3.2 standard deviations and a measured cross-section of sigma s = 4.8 +/- 0.8(stat.)(-1.3)(+1.6)(syst.) pb, which is consistent with the Standard Model expectation. The expected significance for the analysis is 3.9 standard deviations. (C) 2016 CERN for the benefit of the ATLAS Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license.

This Letter presents evidence for single top-quark production in the s-channel using proton-proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS detector at the CERN Large Hadron Collider. The analysis is performed on events containing one isolated electron or muon, large missing transverse momentum and exactly two b-tagged jets in the final state. The analysed data set corresponds to an integrated luminosity of 20.3 fb(-1). The signal is extracted using a maximum-likelihood fit of a discriminant which is based on the matrix element method and optimized in order to separate single-top-quark s-channel events from the main background contributions, which are top-quark pair production and W boson production in association with heavy-flavour jets. The measurement leads to an observed signal significance of 3.2 standard deviations and a measured cross-section of sigma s = 4.8 +/- 0.8(stat.)(-1.3)(+1.6)(syst.) pb, which is consistent with the Standard Model expectation. The expected significance for the analysis is 3.9 standard deviations. (C) 2016 CERN for the benefit of the ATLAS Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license.