TY - JOUR
T1 - Search for flavour-changing neutral currents in processes with one top quark and a photon using 81 fb−1 of pp collisions at s=13TeV with the ATLAS experiment
AU - ATLAS Collaboration
AU - Aad, G
AU - Åkesson, Torsten
AU - Bocchetta, Simona
AU - Bryngemark, Lene
AU - Corrigan, Eric Edward
AU - Doglioni, Caterina
AU - Gregersen, Kristian
AU - Brottmann Hansen, Eva
AU - Hedberg, Vincent
AU - Jarlskog, Göran
AU - Kalderon, Charles
AU - Kellermann, Edgar
AU - Konya, Balazs
AU - Lytken, Else
AU - Mankinen, Katja
AU - Marcon, Caterina
AU - Mjörnmark, Ulf
AU - Mullier, Geoffrey André Adrien
AU - Pöttgen, Ruth
AU - Poulsen, Trine
AU - Skorda, Eleni
AU - Smirnova, Oxana
AU - Zwalinski, L
PY - 2020
Y1 - 2020
N2 - A search for flavour-changing neutral current (FCNC) events via the coupling of a top quark, a photon, and an up or charm quark is presented using 81 fb−1 of proton–proton collision data taken at a centre-of-mass energy of 13 TeV with the ATLAS detector at the LHC. Events with a photon, an electron or muon, a b-tagged jet, and missing transverse momentum are selected. A neural network based on kinematic variables differentiates between events from signal and background processes. The data are consistent with the background-only hypothesis, and limits are set on the strength of the tqγ coupling in an effective field theory. These are also interpreted as 95% CL upper limits on the cross section for FCNC tγ production via a left-handed (right-handed) tuγ coupling of 36 fb (78 fb) and on the branching ratio for t→γu of 2.8×10−5 (6.1×10−5). In addition, they are interpreted as 95% CL upper limits on the cross section for FCNC tγ production via a left-handed (right-handed) tcγ coupling of 40 fb (33 fb) and on the branching ratio for t→γc of 22×10−5 (18×10−5). © 2019 The Author(s)
AB - A search for flavour-changing neutral current (FCNC) events via the coupling of a top quark, a photon, and an up or charm quark is presented using 81 fb−1 of proton–proton collision data taken at a centre-of-mass energy of 13 TeV with the ATLAS detector at the LHC. Events with a photon, an electron or muon, a b-tagged jet, and missing transverse momentum are selected. A neural network based on kinematic variables differentiates between events from signal and background processes. The data are consistent with the background-only hypothesis, and limits are set on the strength of the tqγ coupling in an effective field theory. These are also interpreted as 95% CL upper limits on the cross section for FCNC tγ production via a left-handed (right-handed) tuγ coupling of 36 fb (78 fb) and on the branching ratio for t→γu of 2.8×10−5 (6.1×10−5). In addition, they are interpreted as 95% CL upper limits on the cross section for FCNC tγ production via a left-handed (right-handed) tcγ coupling of 40 fb (33 fb) and on the branching ratio for t→γc of 22×10−5 (18×10−5). © 2019 The Author(s)
U2 - 10.1016/j.physletb.2019.135082
DO - 10.1016/j.physletb.2019.135082
M3 - Article
SN - 0370-2693
VL - 800
JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
M1 - 135082
ER -