In this talk, several measurements in the top-quark sector are presented, obtained from the CMS data collected in 2011 and 2012 at centre-of-mass energies of 7 and 8 TeV. The production cross section of tt¯ pairs is measured in several decay channels: lepton+jets, dilepton and fully hadronic channels, including channels with the τ lepton. Differential cross sections are measured and are provided as a function of various kinematic observables; the results are compared with precise theory calculations. Measurements of several top-quark properties are reported, including the top pair charge asymmetry, the W helicity in top decays, the measurement of the production of tt¯ pairs with W, Z, gamma, the spin correlation and the search for anomalous couplings and flavor-changing neutral currents. The results are compared with predictions from the standard model as well as new physics models. The cross sections for the electroweak production of single top quarks are measured in the t-channel and in association with W-bosons. Measurements of top-quark properties in single top quark production are also presented. The results include the W-helicity in top quark decays and the searches for the s-channel production and anomalous couplings.
Scheda prodotto non validato
Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo