par Sirunyan, A.M.;Beghin, Diego ;Bilin, Bugra ;Brun, Hugues ;Clerbaux, Barbara ;De Lentdecker, Gilles ;Delannoy, Hugo ;Dorney, Brian ;Favart, Laurent ;Grebenyuk, Anastasia ;Kalsi, Amandeep Kaur ;Luetic, Jelena ;Popov, Andrey ;Postiau, Nicolas ;Starling, Elizabeth Rose ;Thomas, Laurent ;Vander Velde, Catherine ;Vanlaer, Pascal ;Vannerom, David ;Wang, Qun ;Malara, Andrea ; [et al.]
Référence The Journal of high energy physics, 2020, 3, 56
Publication Publié, 2020-03-01
Référence The Journal of high energy physics, 2020, 3, 56
Publication Publié, 2020-03-01
Article révisé par les pairs
Résumé : | A measurement of the inclusive cross section of top quark pair production in association with a Z boson using proton-proton collisions at a center-of-mass energy of 13 TeV at the LHC is performed. The data sample corresponds to an integrated luminosity of 77.5 fb−1, collected by the CMS experiment during 2016 and 2017. The measurement is performed using final states containing three or four charged leptons (electrons or muons), and the Z boson is detected through its decay to an oppositely charged lepton pair. The production cross section is measured to be σ(t t ¯ Z) = 0.95 ± 0.05 (stat) ± 0.06 (syst) pb. For the first time, differential cross sections are measured as functions of the transverse momentum of the Z boson and the angular distribution of the negatively charged lepton from the Z boson decay. The most stringent direct limits to date on the anomalous couplings of the top quark to the Z boson are presented, including constraints on the Wilson coefficients in the framework of the standard model effective field theory. [Figure not available: see fulltext.] |