Study of τ-reconstruction effects on a Higgs-CP-measurement at ATLAS

CP-mixing in the Higgs-to-fermion couplings is predicted by a number of important Beyond the Standard Model theories such as Supersymmetry, and is so far not excluded by LHC measurements. The mixing angle can be measured in the H → ττ channel, where both taus decay hadronically, via the reconstruction of decay planes spanned by the decay products. The measurement relies on the 4-momentum reconstruction of the tau decay products and the purity of reconstructing specific decay modes. I present results of a study of the impact of tau reconstruction effects on the sensitivity of a prospective CP-mixing measurement.