Top pair cross section in dileptons

The cross section for top quark pair production is measured in proton-proton collisions at $\sqrt{s} = 7\rm~TeV$ in a data sample corresponding to 1.14 fb$^{-1}$ of integrated luminosity collected by the CMS experiment in 2011. The measurement is performed with events with two energetic leptons (electrons or muons) as well as with identified b-quark jets in the final state. The measured cross section is found to be 169.9 $\pm$ 3.9 (stat.) $\pm$ 16.3 (syst.) $\pm$ 7.6 (lumi.) pb, in agreement with theoretical predictions.