Physics with Tau-Lepton Final States in ATLAS

Heading into its third year of data-taking ATLAS already published a large number of measurements and searches for processes with $\tau$ leptons in the final state. In this note a broad overview over the ATLAS physics programme involving $\tau$-leptons will be given. Searches for a SM Higgs boson, charged Higgs bosons as proposed in supersymmetric models and searches for supersymmetry in events with tau leptons are presented as well as Standard Model measurements. The first measurement of the $\tau$ polarization in $W\rightarrow\tau\nu$ decays at a hadron collider and the challenging measurement of the $t\bar{t}$ cross-section in the $\tau_hl$ final state are discussed. All observations agree well with the SM prediction.