Search for direct production of electroweakinos in final states with one lepton, jets and missing transverse momentum and in p p collisions at √s = 13 TeV with the ATLAS detector

Two searches for electroweak production of chargino-neutralino, χ ̃1± χ ̃20, and chargino-chargino, χ ̃1+ χ ̃1−, pairs are presented. In both scenarios the chargino decays into a W boson and the lightest neutralino χ ̃1± → W± χ ̃10, and second-to-lightest decays into a Z boson and the lightest neutralino χ ̃20 → Z χ ̃10. The signal signature for both processes is characterized by a single isolated lepton, at least two jet, and missing transverse energy. The searches use 139 fb−1 of √s = 13 TeV proton–proton collisions data collected by the ATLAS detector at the Large Hadron Collider between 2015 and 2018. The search observed no deviation with respect to the Standard Model expectations, and exclusion limits have been set in the (m(χ ̃1±/χ ̃20), m(χ ̃10)) mass plane. For the χ ̃1+ χ ̃1− model, chargino masses ranging from 260 to 520 GeV can be excluded for a massless χ ̃10 at 95% CL, while for the χ ̃1± χ ̃20 process, degenerate chargino/neutralino masses ranging from 260 to 420 GeV can be excluded for a massless χ ̃10 at 95% CL.