Measurements of the ttbar cross section in the dilepton channels with 100 inverse picobarns using the CMS detector

We present an analysis for the measurement of the top quark pair ($t\bar{t}$) production cross-section at $\sqrt{s}= 14\;TeV$ using dilepton final states. The event selection, based on simple cuts is described and an almost background free final sample can be derived. For a total integrated luminosity of $100\;pb^{-1}$, the cross-section is extracted by means of a robust event counting method and the associated statistical uncertainty is found to be 8\%.