First measurement of the top quark pair production cross section in the dilepton channel with tau leptons in the final state in pp collisions at sqrt(s)=7~TeV

We present a measurement of the \ttbar production cross section in dilepton events with one muon and one hadronically decaying tau lepton from the decay $\ttbar\rightarrow (\mu\nu_\mu) (\tau_h \nu_\tau) b\bar{b}$. This is the first measurement of the \ttbar cross section explicitly including tau leptons in proton-proton collisions at $\sqrt{s}=7$~TeV. The data sample corresponds to an integrated luminosity of 1.09~fb$^{-1}$ collected by the CMS detector. The measured value $\sigma_{\ttbar} = 148.7 \pm 23.6({\rm stat.}) \pm 26.0({\rm syst.}) \pm 8.9 ({\rm lumi.})~{\rm pb}$ is consistent with predictions from the standard model.