TY  - JOUR
AU  - ATLAS Collaboration (Aad, G. et al
AU  - Amos, K. R.
AU  - Aparisi Pozo, J. A.
AU  - Bailey, A. J.
AU  - Cabrera Urban, S.
AU  - Cantero, J.
AU  - Cardillo, F.
AU  - Castillo Gimenez, V.
AU  - Costa, M. J.
AU  - Didenko
AU  - Escobar, C.
AU  - Fiorini, L.
AU  - Fullana Torregrosa, E.
AU  - Fuster, J.
AU  - Garcia, C.
AU  - Garcia Navarro, J. E.
AU  - Gomez Delegido, A. J.
AU  - Gonzalez de la Hoz, S.
AU  - Gonzalvo Rodriguez, G. R.
AU  - Guerrero Rojas, J. G. R.
AU  - Higon-Rodriguez, E.
AU  - Lacasta, C.
AU  - Lozano Bahilo, J. J.
AU  - Marti-Garcia, S.
AU  - Martinez Agullo, P.
AU  - Miralles Lopez, M.
AU  - Mitsou, V. A.
AU  - Monsonis Romero, L.
AU  - Moreno Llacer, M.
AU  - Munoz Perez, D.
AU  - Navarro-Gonzalez, J.
AU  - Poveda, J.
AU  - Prades Ibañez, A.
AU  - Rubio Jimenez, A.
AU  - Ruiz-Martinez, A.
AU  - Sabatini, P.
AU  - Salt, J.
AU  - Sanchez Sebastian, V.
AU  - Sayago Galvan, I.
AU  - Senthilkumar, V.
AU  - Soldevila, U.
AU  - Sanchez, J.
AU  - Torro Pastor, E.
AU  - Valero, A.
AU  - Valls Ferrer, J. A.
AU  - Varriale, L.
AU  - Villaplana Perez, M.
AU  - Vos, M.
PY  - 2023
DA  - 2023//
TI  - Search for flavour-changing neutral-current couplings between the top quark and the photon with the ATLAS detector at root s=13 TeV
T2  - Phys. Lett. B
JO  - Physics Letters B
SP  - 137379
EP  - 22pp
VL  - 842
PB  - Elsevier
AB  - This letter documents a search for flavour-changing neutral currents (FCNCs), which are strongly sup-pressed in the Standard Model, in events with a photon and a top quark with the ATLAS detector. The analysis uses data collected in pp collisions at & RADIC;s =13 TeV during Run 2 of the LHC, corresponding to an integrated luminosity of 139 fb-1. Both FCNC top-quark production and decay are considered. The final state consists of a charged lepton, missing transverse momentum, a b-tagged jet, one high-momentum photon and possibly additional jets. A multiclass deep neural network is used to classify events either as signal in one of the two categories, FCNC production or decay, or as background. No significant ex-cess of events over the background prediction is observed and 95% CL upper limits are placed on the strength of left-and right-handed FCNC interactions. The 95% CL bounds on the branching fractions for the FCNC top-quark decays, estimated (expected) from both top-quark production and decay, are B(t & RARR; u & gamma; ) < 0.85 (0.88+0.37 -0.25) x 10-5 and B(t & RARR; c & gamma; ) < 4.2 (3.40+1.35-0.95) x 10-5 for a left-handed tq & gamma; cou-pling, and B(t & RARR; u & gamma; ) < 1.2 (1.20+0.50 -0.33) x10-5 and B(t & RARR; c & gamma; ) < 4.5 (3.70+1.47 -1.03) x10-5 for a right-handed coupling.
SN  - 0370-2693
UR  - https://arxiv.org/abs/2205.02537
UR  - https://doi.org/10.1016/j.physletb.2022.137379
DO  - 10.1016/j.physletb.2022.137379
LA  - English
N1  - WOS:001023760300001
ID  - ATLASCollaborationAad_etal2023
ER  -