Measurement of τ polarization in W→τν decays with the ATLAS detector in pp collisions at

In this paper, a measurement of τ polarization in W→τν decays is presented. It is measured from the energies of the decay products in hadronic τ decays with a single final state charged particle. The data, corresponding to an integrated luminosity of 24 pb−1, were collected by the ATLAS experiment at the Large Hadron Collider in 2010. The measured value of the τ polarization is $${P_{\tau}}= -1.06 \pm0.04\ (\mathrm{stat})\;^{+0.05}_{-0.07}\ …