Measurement of the production cross-section of a single top quark in association with a W boson at 8 TeV with the ATLAS experiment

0470742 - FZÚ 2017 RIV US eng J - Článek v odborném periodiku
Aad, G. - Abbott, B. - Abdallah, J. - Chudoba, Jiří - Havránek, Miroslav - Hejbal, Jiří - Jakoubek, Tomáš - Kepka, Oldřich - Kupčo, Alexander - Kůs, Vlastimil - Lokajíček, Miloš - Lysák, Roman - Marčišovský, Michal - Mikeštíková, Marcela - Němeček, Stanislav - Penc, Ondřej - Šícho, Petr - Staroba, Pavel - Svatoš, Michal - Taševský, Marek - Vrba, Václav … celkem 2870 autorů
Measurement of the production cross-section of a single top quark in association with a W boson at 8 TeV with the ATLAS experiment.
Journal of High Energy Physics. Roč. 2016, č. 1 (2016), s. 1-50, č. článku 064. ISSN 1029-8479. E-ISSN 1029-8479
Institucionální podpora: RVO:68378271
Klíčová slova: CERN LHC Coll * ATLAS * channel cross section * measured * standard model * validity test * acceptance * CKM matrix * background * CERN Lab
Kód oboru RIV: BF - Elementární částice a fyzika vys. energií
Impakt faktor: 6.063, rok: 2016

The cross-section for the production of a single top quark in association with a W boson in proton-proton collisions at s√=8TeV is measured. The dataset corresponds to an integrated luminosity of 20.3 fb−1, collected by the ATLAS detector in 2012 at the Large Hadron Collider at CERN. Events containing two leptons and one central b-jet are selected. The W t signal is separated from the backgrounds using boosted decision trees, each of which combines a number of discriminating variables into one classifier. Production of W t events is observed with a significance of 7.7σ. The cross-section is extracted in a profile likelihood fit to the classifier output distributions. The W t cross-section, inclusive of decay modes, is measured to be 23.0 ± 1.3(stat.)+ 3.2− 3.5 (syst.)±1.1(lumi.) pb. The measured cross-section is used to extract a value for the CKM matrix element |Vtb | of 1.01 ± 0.10 and a lower limit of 0.80 at the 95% confidence level.
Trvalý link: http://hdl.handle.net/11104/0268311