Naslov
Observation of top quark pairs produced in association with a vector boson in pp collisions at sqrt(s) = 8 TeV

Autori
Khachatryan, Vardan ; ... ; Morović, Srećko ; Ferenček, Dinko ; Đurić, Senka ; Godinović, Nikola ; Lelas, Damir ; Puljak, Ivica ; Ribeiro Cipriano, Pedro Miguel ; Antunović, Željko ; Kovač, Marko ; Brigljević, Vuko ; Kadija, Krešo ; Luetić, Jelena ; Mićanović, Saša ; Sudić, Lucija ; ... ; Woods, Nate

Izvornik
Journal of High Energy Physics (1029-8479) 1 (2016); 096-096

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
High energy physics ; Experimental particle physics ; LHC ; CMS ; Standard Model

Sažetak
Measurements of the cross sections for top quark pairs produced in association with a W or Z boson are presented, using 8 TeV pp collision data corresponding to an integrated luminosity of 19.5 inverse femtobarns, collected by the CMS experiment at the LHC. Final states are selected in which the associated W boson decays to a charged lepton and a neutrino or the Z boson decays to two charged leptons. Signal events are identified by matching reconstructed objects in the detector to specific final state particles from ttW or ttZ decays. The ttW cross section is measured to be 382 +117 -102 fb with a significance of 4.8 standard deviations from the background-only hypothesis. The ttZ cross section is measured to be 242 +65 -55 fb with a significance of 6.4 standard deviations from the background-only hypothesis. These measurements are used to set bounds on five anomalous dimension-six operators that would affect the ttW and ttZ cross sections.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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