Search for the direct production of charginos and neutralinos in final states with tau leptons in √s=13TeV pp 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 13TeV.Nosignificant 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 ˜ τL 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 ˜ τL mass between the masses of the ˜χ ± 1 and the ˜χ 0 1 .