Searches for Higgsinos and related challenges in ATLAS

Natural models of Supersymmetry (SUSY) typically favor existence of light higgsinos. Models in which the only accessible SUSY particles are charginos and neutralinos that are predominantly higgsinos tend to have low mass splitting between these particles. Such models, commonly referred to as compressed models, lead to final states including low-momentum leptons and disappearing tracks that are experimentally challenging to characterize. This talk will present the latest results from Higgsino searches that are conducted taking advantage of the large pp collision dataset recorded by ATLAS in 2015 and 2016 at a centre-of-mass energy of 13 TeV.