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 13 TeV 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 σ(t ̄tW) = 0.77+0.12(stat)+0.13(syst)pb and σ(t ̄tZ) = 0.99+0.09-0.08(stat)+0.12-0.10(syst)pb. The expected (observed) signal significance for the t ̄tW production in same-sign dilepton channel is found to be 4.5 (5.3) standard deviations, while for the t ̄tZ production in three- and four-lepton channels both the expected and the observed significances 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 coefficients for eight dimension-six operators describing new interactions that would modify t ̄tW and t ̄tZ production.
Measurement of the cross section for top quark pair production in association with a W or Z boson in proton-proton collisions at √s=13 TeV
Ravera, F.;Meridiani, P.;Amapane, N.;Argiro, S.;Bellan, R.;Costa, M.;Covarelli, R.;Kiani, B.;Migliore, E.;Monaco, V.;Monteil, E.;Obertino, M. M.;Pacher, L.;Pinna Angioni, G. L.;Romero, A.;Sacchi, R.;Sola, V.;Solano, A.;Rumerio, P.;
2018-01-01
Abstract
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 13 TeV 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 σ(t ̄tW) = 0.77+0.12(stat)+0.13(syst)pb and σ(t ̄tZ) = 0.99+0.09-0.08(stat)+0.12-0.10(syst)pb. The expected (observed) signal significance for the t ̄tW production in same-sign dilepton channel is found to be 4.5 (5.3) standard deviations, while for the t ̄tZ production in three- and four-lepton channels both the expected and the observed significances 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 coefficients for eight dimension-six operators describing new interactions that would modify t ̄tW and t ̄tZ production.File | Dimensione | Formato | |
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1.CMS2018_Article_MeasurementOfTheCrossSectionFo.pdf
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