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.]

Sirunyan, A.M., Tumasyan, A., Adam, W., Ambrogi, F., Bergauer, T., Brandstetter, J., et al. (2020). Measurement of top quark pair production in association with a Z boson in proton-proton collisions at √s = 13 TeV. JOURNAL OF HIGH ENERGY PHYSICS, 2020(3) [10.1007/JHEP03(2020)056].

Measurement of top quark pair production in association with a Z boson in proton-proton collisions at √s = 13 TeV

Ciocci M. A.;Messineo A.;
2020-01-01

Abstract

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.]
2020
Sirunyan, A.M., Tumasyan, A., Adam, W., Ambrogi, F., Bergauer, T., Brandstetter, J., et al. (2020). Measurement of top quark pair production in association with a Z boson in proton-proton collisions at √s = 13 TeV. JOURNAL OF HIGH ENERGY PHYSICS, 2020(3) [10.1007/JHEP03(2020)056].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/1327238