ÚTEFČVUT Ústav technické a experimentální fyziky ČVUT v PrazeInstitute of Experimental and Applied Physics, CTU in Prague

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
Klíčová slovaKeywords
parton distribution, hadron colliders, doublet models, cross section, root-s=7 tev, DECAY, Collision, lhc, coupling, standard
ExperimentCollaboration
ATLAS
DOIDOI
10.1140/epjc/s10052-016-3876-4
Časopis / citaceJournal / citation
The European Physical Journal C 76(2), 55 (2016) · ISSN 1434-6044
RokYear
2016
JazykLanguage
eng
ZáznamyRecords
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
CitovánoCited by
96 (INSPIRE-HEP)
2014: 12015: 62016: 222017: 182018: 132019: 102020: 52021: 42022: 92023: 22024: 42025: 2
Citace ke staženíDownload citation
TXT · BibTeX

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).

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