Naslov
Measurement of the cross section for top quark pair production in association with a W or Z boson in proton-proton collisions at root s=13 TeV

Autori
Sirunyan, Albert ; ... ; Đurić, Senka ; Lelas, Damir ; Godinović, Nikola ; Puljak, Ivica ; Šćulac, Toni ; Mesić, Benjamin ; Šuša, Tatjana ; Kovač, Marko ; Ferenček, Dinko ; Antunović, Željko ; Starodumov, Andrey ; Brigljević, Vuko ; Luetić, Jelena ; Kadija, Krešo ; ... ; Woods, Nate

Kolaboracija
CMS Collaboration

Izvornik
The Journal of high energy physics (1126-6708) 08 (2018); 011, 50

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

Ključne riječi
high energy physics ; experimental particle physics ; LHC ; CMS ; standard model

Sažetak
A measurement is performed of the cross section of top quark pair production in association with a W or Z boson using proton-proton collisions at a center-of-mass energy of 13TeV at the LHC. The data sample corresponds to an integrated luminosity of 35.9 fb(-1), collected by the CMS experiment in 2016. The measurement is performed in the same-sign dilepton, three- and four-lepton final states. The production cross sections are measured to be sigma(t (t) over barW) = 0.77(-0.11)(+0.12)(stat)(-0.12) (+0.13) pb and sigma(t (t) over barZ) = 0.99(-0.08)(+0.09) (stat)(-0.10)(+0.12) (syst) pb. The expected (observed) signal signi fi cance for the sigma(t (t) over barW production in same-sign dilepton channel is found to be 4.5 (5.3) standard deviations, while for the t (t) over barZ production in three- and four- lepton channels both the expected and the observed signi fi cances are found to be in excess of 5 standard deviations. The results are in agreement with the standard model predictions and are used to constrain the Wilson coe ffi cients for eight dimension-six operators describing new interactions that would modify t (t) over barW and t (t) over barZ production.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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