Search for electroweak production of supersymmetric particles in final states with at least two hadronically decaying taus and missing transverse momentum with the ATLAS detector in proton-proton collisions at $\sqrt{s}=8$ TeV

Results of a search for the production of weakly coupled supersymmetric particles decaying into final states with at least two hadronically decaying taus and missing transverse momentum are presented. The analysis uses the complete 2012 data sample of $\sqrt{s}=8$ TeV proton-proton collisions recorded with the ATLAS detector at the CERN Large Hadron Collider, corresponding to a total integrated luminosity of $20.7 fb^{-1}$. No deviation from the Standard Model expectation is observed. Exclusion limits at 95% confidence level are derived in the context of the phenomenological Minimal Supersymmetric Standard Model and Simplified Models characterized by the presence of low mass staus. For Simplified Models, chargino masses up to 350 GeV are excluded for a massless lightest neutralino in the scenario of direct production of wino-like chargino pairs decaying into the lightest neutralino via an intermediate on-shell tau slepton. In the case of pair production of degenerate charginos and next-to-lightest neutralinos, masses up to 330 (300) GeV are excluded for lightest neutralino masses below 50 (100) GeV.