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 of (). 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 of ().

Aad G., A.B. (2020). Search for flavour-changing neutral currents in processes with one top quark and a photon using 81 fb−1 of pp collisions at √s = 13 TeV with the ATLAS experiment. PHYSICS LETTERS. SECTION B, 800, 135082-1-135082-21 [10.1016/j.physletb.2019.135082].

Search for flavour-changing neutral currents in processes with one top quark and a photon using 81 fb−1 of pp collisions at √s = 13 TeV with the ATLAS experiment

Alberghi G. L.;Alfonsi F.;Bellagamba L.;Bindi M.;Boscherini D.;Cabras G.;Caforio D.;De Castro S.;Di Sipio R.;Fabbri L.;Franchini M.;Gabrielli A.;Giacobbe B.;Lasagni Manghi F.;Macchiolo A.;Massa L.;Monzani S.;Polini A.;Rinaldi L.;Romano M.;Sbarra C.;Sbrizzi A.;Semprini-Cesari N.;Sioli M.;Todome K.;Ucchielli G.;Valentinetti S.;Villa M.;Vittori C.;Vivarelli I.;Zoccoli A.;
2020

Abstract

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 of (). 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 of ().
2020
Aad G., A.B. (2020). Search for flavour-changing neutral currents in processes with one top quark and a photon using 81 fb−1 of pp collisions at √s = 13 TeV with the ATLAS experiment. PHYSICS LETTERS. SECTION B, 800, 135082-1-135082-21 [10.1016/j.physletb.2019.135082].
Aad G., Abbott B., Abbott D.C., Abed Abud A., Abeling K., Abhayasinghe D.K., Abidi S.H., Abouzeid O.S., Abraham N.L., Abramowicz H., Abreu H., Abulait...espandi
File in questo prodotto:
File Dimensione Formato  
1-s2.0-S0370269319308044-main.pdf

accesso aperto

Tipo: Versione (PDF) editoriale
Licenza: Licenza per Accesso Aperto. Creative Commons Attribuzione (CCBY)
Dimensione 1.44 MB
Formato Adobe PDF
1.44 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/727681
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 31
  • ???jsp.display-item.citation.isi??? 12
social impact