Measurement of the W→τντ cross section in pp collisions at s=7 TeV with the ATLAS experiment

The cross section for the production of W bosons with subsequent decay W→τντ is measured with the ATLAS detector at the LHC. The analysis is based on a data sample that was recorded in 2010 at a proton–proton center-of-mass energy of s=7 TeV and corresponds to an integrated luminosity of 34 pb−1. The cross section is measured in a region of high detector acceptance and then extrapolated to the full phase space. The product of the total W production cross section and the W→τντ branching ratio is measured to be σW→τντtot=11.1±0.3(stat)±1.7(syst)±0.4(lumi) nb.