Search for direct stau production in events with two hadronic tau leptons in √s = 13 TeV pp collisions with the ATLAS detector

A search for the direct production of staus in final states with two hadronically decaying tau leptons is presented. The analysis uses a dataset of pp collisions corresponding to an integrated luminosity of 139 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 direct production of two mass-degenerate staus in simplified models with each stau decaying into the lightest neutralino and one tau lepton. Stau masses from 120 GeV to 390 GeV are excluded at 95 % confidence level for a massless lightest neutralino.