Search for electroweak production of supersymmetric particles in final states with tau leptons in $\sqrt{s} =$ 13TeV pp collisions with the ATLAS detector

A search for the electroweak production of charginos and neutralinos in final states with at least two hadronically decaying tau leptons is presented. The analysis uses a dataset of proton$-$proton collisions corresponding to an integrated luminosity of 14.8 fb$^{-1}$, recorded with the ATLAS detector at the Large Hadron Collider at a centre-of-mass energy of $\sqrt{s} =$ 13 TeV. No significant deviation from the Standard Model expectation is observed. Limits are derived in scenarios of $\tilde\chi^+_1 \tilde\chi^-_1$ pair production and $\tilde\chi^\pm_1 \tilde\chi^0_2$ and $\tilde\chi^+_1 \tilde\chi^-_1$ associated production. Common $\tilde\chi^\pm_1$-$\tilde\chi^0_2$ masses up to 580 and 700 GeV respectively are excluded at 95 % confidence level assuming a massless $\tilde\chi^0_1$.