ATLAS collaboration (3034 authors)Aguilar-Saavedra, Juan AntonioAmaral, PedroAnjos, NunoCarvalho, JoãoCastro, Nuno FilipeConde Muiño, PatriciaDo Valle Wemans, AndréFiolhais, MiguelGomes, AgostinhoGonçalo, RicardoJorge, PedroLopes, LourencoMachado Miguens, JoanaMaio, AméliaManeira, JoséOliveira, Miguel AlfonsoOnofre, AntónioPalma, AlbertoPina, João AntonioPinto, BelmiroSantos, HelenaSaraiva, JoãoSilva, JoséSoares, MaraVeloso, FilipeWolters, Helmut2019-02-032019-02-032012-02http://dx.doi.org/10.1103/PhysRevLett.108.261802http://hdl.handle.net/10400.26/26099A search is presented for production of a heavy up-type quark (t') together with its antiparticle, assuming subsequent decay to a W boson and a b quark, t't'bar -> W+b W-bbar. The search is based on 1.04 fb^-1 of proton-proton collisions at sqrt(s) = 7 TeV collected by the ATLAS detector at the CERN Large Hadron Collider. Data are analyzed in the lepton+jets final state, characterized by a high transverse momentum isolated electron or muon, high missing transverse momentum and at least three jets. No significant excess of events above the background expectation is observed. A 95% C.L. lower limit is set at m(t') > 404 GeV.engSearch for pair production of a heavy up-type quark decaying to a W boson and a b quark in the lepton+jets channel with the ATLAS detectorjournal article2019-02-03