Rights statement: © CERN for the benefit of the ATLAS collaboration 2016. This article is published with open access at Springerlink.com EPJC is an open-access journal funded by SCOAP3 and licensed under CC BY 4.0
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Available under license: CC BY: Creative Commons Attribution 4.0 International License
Final published version
Licence: CC BY: Creative Commons Attribution 4.0 International License
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Search for single top-quark production via flavour-changing neutral currents at 8 TeV with the ATLAS detector
AU - Barton, Adam Edward
AU - Beattie, Michael
AU - Borissov, Guennadi
AU - Bouhova-Thacker, Evelina Vassileva
AU - Dearnaley, William
AU - Fox, Harald
AU - Grimm, Kathryn Ann Tschann
AU - Henderson, Robert Charles William
AU - Hughes, Gareth
AU - Jones, Roger William Lewis
AU - Kartvelishvili, Vakhtang
AU - Long, Robin Eamonn
AU - Love, Peter Allan
AU - Maddocks, Harvey
AU - Skinner, Malcolm
AU - Smizanska, Maria
AU - Walder, James William
AU - Wharton, Andy
AU - The ATLAS collaboration
PY - 2016/1/29
Y1 - 2016/1/29
N2 - 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 8 TeV and corresponding to an integrated luminosity of 20.3 fb−1−1 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→Wbt→Wb branching fraction is set. The observed 95 % CL limit is σqg→t×B(t→Wb)<3.4pbσqg→t×B(t→Wb)<3.4pb and the expected 95 % CL limit is σqg→t×B(t→Wb)<2.9pbσqg→t×B(t→Wb)<2.9pb. 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 κugt/Λ<5.8×10−3TeV−1κugt/Λ<5.8×10−3TeV−1 and κcgt/Λ<13×10−3TeVκcgt/Λ<13×10−3TeV and on the branching fractions B(t→ug)<4.0×10−5B(t→ug)<4.0×10−5and B(t→cg)<20×10−5B(t→cg)<20×10−5.
AB - 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 8 TeV and corresponding to an integrated luminosity of 20.3 fb−1−1 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→Wbt→Wb branching fraction is set. The observed 95 % CL limit is σqg→t×B(t→Wb)<3.4pbσqg→t×B(t→Wb)<3.4pb and the expected 95 % CL limit is σqg→t×B(t→Wb)<2.9pbσqg→t×B(t→Wb)<2.9pb. 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 κugt/Λ<5.8×10−3TeV−1κugt/Λ<5.8×10−3TeV−1 and κcgt/Λ<13×10−3TeVκcgt/Λ<13×10−3TeV and on the branching fractions B(t→ug)<4.0×10−5B(t→ug)<4.0×10−5and B(t→cg)<20×10−5B(t→cg)<20×10−5.
U2 - 10.1140/epjc/s10052-016-3876-4
DO - 10.1140/epjc/s10052-016-3876-4
M3 - Journal article
VL - 76
JO - European Physical Journal C: Particles and Fields
JF - European Physical Journal C: Particles and Fields
SN - 1434-6044
IS - 2
M1 - 55
ER -