Search for the direct production of charginos and neutralinos in final states with tau leptons in $\sqrt{s}$ =13 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with at least two hadronically decaying tau leptons is presented. The analysis uses a dataset of pp collisions corresponding to an integrated luminosity of 36.1 fb -1 , recorded with the ATLAS detector at the Large Hadron Collider at a centre-of-mass energy of 13 TeV. No significant deviation from the expected Standard Model background is observed. Limits are derived in scenarios of $ \tilde{X} $$ \mathbb +\atop{1}$$ \tilde{X}$$ \mathbb -\atop{1}$ pair production and of $ \tilde{X} $$ \mathbb ±\atop{1}$$ \tilde{X}$$ \mathbb 0\atop{2}$ and $ \tilde{X} $$ \mathbb +\atop{1}$$ \tilde{X}$$ \mathbb -\atop{1}$ production in simplified models where the neutralinos and charginos decay solely via intermediate left-handed staus and tau sneutrinos, and the mass of the $ \tilde{τ} $ L state is set to be halfway between the masses of the $ \tilde{X} $$ \mathbb ±\atop{1}$ and the $ \tilde{X}$$ \mathbb 0\atop{1}$. Chargino masses up to 630 GeV are excluded at 95% confidence level in the scenario of direct production of $ \tilde{X} $$ \mathbb +\atop{1}$$ \tilde{X}$$ \mathbb -\atop{1}$ for a massless $ \tilde{X}$$ \mathbb 0\atop{1}$. Common $ \tilde{X} $$ \mathbb ±\atop{1}$ and $ \tilde{X}$$ \mathbb 0\atop{2}$ masses up to 760 GeV are excluded in the case of production of $ \tilde{X} $$ \mathbb ±\atop{1}$$ \tilde{X}$$ \mathbb 0\atop{2}$ and $ \tilde{X} $$ \mathbb +\atop{1}$$ \tilde{X}$$ \mathbb -\atop{1}$ assuming a massless $ \tilde{X}$$ \mathbb 0\atop{1}$. Exclusion limits for additional benchmark scenarios with large and small mass-splitting between the$ \tilde{X} $$ \mathbb ±\atop{1}$ and the $ \tilde{X}$$ \mathbb 0\atop{1}$ are also studied by varying the $ \tilde{τ} $ L mass between the masses of the$ \tilde{X} $$ \mathbb ±\atop{1}$ and the $ \tilde{X}$$ \mathbb 0\atop{1}$.