Search for single top-quark production via flavour-changing neutral currents at 8TeV with the ATLAS detector
- NázevTitle
- Search for single top-quark production via flavour-changing neutral currents at 8TeV with the ATLAS detectorSearch for single top-quark production via flavour-changing neutral currents at 8TeV with the ATLAS detector
- 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, D. Tureček, V. Vacek, M. Vlasak, P. Vokáč, Z. Vykydal, M. Zeman
- DOIDOI
- 10.1140/epjc/s10052-016-3876-4
- Časopis / citaceJournal / citation
- European Physical Journal C. 2016, 76(2), ISSN 1434-6044.
- RokYear
- 2016
- JazykLanguage
- eng
- WoSWoS
- 000375277900001
- ScopusScopus
- 2-s2.0-84958164056
- RIVRIV
- RIV/68407700:21220/16:00309069!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
A search for single top-quark production via flavour-changing neutral current processes from gluon plus up- or charm-quark initial states in proton-proton collisions at the LHC is presented. Data collected with the ATLAS detector in 2012 at a centre-of-mass energy of 8TeV and corresponding to an integrated luminosity of 20.3 fb(-1) are used. Candidate events for a top quark decaying into a lepton, a neutrino and a jet are selected and classified into signal- and background-like candidates using a neural network. No signal is observed and an upper limit on the production cross-section multiplied by the t -> Wb branching fraction is set. The observed 95% CL limit is sigma(qg -> t) x B(t -> Wb) < 3.4 pb and the expected 95% CL limit is sigma(qg -> t) x B(t -> Wb) < 2.9 pb. The observed limit can be interpreted as upper limits on the coupling constants of the flavour-changing neutral current interactions divided by the scale of new physics kappa(ugt)/Lambda < 5.8 x 10(-3) TeV-1 and kappa(cgt)/Lambda < 13x10(-3) TeV and on the branching fractions B(t -> ug) < 4.0 x 10(-5) and B(t -> cg) < 20 x 10(-5).
A search for single top-quark production via flavour-changing neutral current processes from gluon plus up- or charm-quark initial states in proton-proton collisions at the LHC is presented. Data collected with the ATLAS detector in 2012 at a centre-of-mass energy of 8TeV and corresponding to an integrated luminosity of 20.3 fb(-1) are used. Candidate events for a top quark decaying into a lepton, a neutrino and a jet are selected and classified into signal- and background-like candidates using a neural network. No signal is observed and an upper limit on the production cross-section multiplied by the t -> Wb branching fraction is set. The observed 95% CL limit is sigma(qg -> t) x B(t -> Wb) < 3.4 pb and the expected 95% CL limit is sigma(qg -> t) x B(t -> Wb) < 2.9 pb. The observed limit can be interpreted as upper limits on the coupling constants of the flavour-changing neutral current interactions divided by the scale of new physics kappa(ugt)/Lambda < 5.8 x 10(-3) TeV-1 and kappa(cgt)/Lambda < 13x10(-3) TeV and on the branching fractions B(t -> ug) < 4.0 x 10(-5) and B(t -> cg) < 20 x 10(-5).