Search for the direct production of charginos and neutralinos in final states with tau leptons in √s=13TeVpp collisions with the ATLAS detector

Abstract

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 χ˜ + 1 χ˜ − 1 pair production and of χ˜ ± 1 χ˜ 0 2 and χ˜ + 1 χ˜ − 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 τ˜L state is set to be halfway between the masses of the χ˜ ± 1 and the χ˜ 0 1 . Chargino masses up to 630 GeV are excluded at 95% confidence level in the scenario of direct production of χ˜ + 1 χ˜ − 1 for a massless χ˜ 0 1 . Common χ˜ ± 1 and χ˜ 0 2 masses up to 760 GeV are excluded in the case of production of χ˜ ± 1 χ˜ 0 2 and χ˜ + 1 χ˜ − 1 assuming a massless χ˜ 0 1 . Exclusion limits for additional benchmark scenarios with large and small mass-splitting between the χ˜ ± 1 and the χ˜ 0 1 are also studied by varying the τ˜L mass between the masses of the χ˜ ± 1 and the χ˜ 0 1 .