Top pair cross section in tau+jets

This document presents a measurement of the top-antitop pair production cross section in proton-proton collisions at a center-of-mass energy of 7 TeV using data collected by the CMS experiment at the Large Hadron Collider. The measurement is performed in events with at least four energetic jets, at least one of them being b-tagged, and one hadronic tau candidate in the final state. The analysed data sample corresponds to an integrated luminosity of 3.9 \fbinv recorded by a dedicated multijet trigger including tau identification. A neural network has been developed to separate the top-antitop signal from the W-plus-jets and QCD multijet backgrounds. The measured value of $\sigma_{t\bar{t}} = 156 \pm 12\,\textrm{(stat.)}\pm 33\,\textrm{(sys.)}\pm 3\,\textrm{(lumi)}\,\textrm{pb}$ is consistent with the standard model prediction.