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Abstract

Three searches for the direct production of τ -sleptons or charginos and neutralinos in fnal states with at least two hadronically decaying τ -leptons are presented. For chargino and neutralino production, decays via intermediate τ -sleptons or W and h bosons are considered. 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 signifcant deviation from the expected Standard Model background is observed and supersymmetric particle mass limits at 95% confdence level are obtained in simplifed models. For direct production of χ˜ + 1 χ˜ − 1 , chargino masses are excluded up to 970 GeV, while χ˜ ± 1 and χ˜ 0 2 masses up to 1160 GeV (330 GeV) are excluded for χ˜ ± 1 χ˜ 0 2 /χ˜ + 1 χ˜ − 1 production with subsequent decays via τ -sleptons (W and h bosons). Masses of τ -sleptons up to 500 GeV are excluded for mass degenerate τ˜L,R scenarios and up to 425 GeV for τ˜L-only scenarios. Sensitivity to τ˜R-only scenarios from the ATLAS experiment is presented here for the frst time, with τ˜R masses excluded up to 350 GeV.