Measurement of differential top-quark-pair production cross sections in pp collisions at √ s =7 TeV
Normalised differential top-quark-pair production cross sections are measured in pp collisions at a centreof- mass energy of 7 TeVat the LHC with the CMS detector using data recorded in 2011 corresponding to an integrated luminosity of 5.0 fb−1. The measurements are performed in the lepton + jets decay channels (e + jets and μ + jets) and the dilepton decay channels (e+e−, μ + μ −, and μ ±e∓). The t¯t differential cross section is measured as a function of kinematic properties of the final-state charged leptons and jets associated to b quarks, as well as those of the top quarks and the t¯t system. The data are compared with several predictions from perturbative QCD calculations up to approximate next-to-next-to-leading-order precision. No significant deviations from the standard model are observed.