Abstract
Supersymmetry (SUSY) is an extension of the Standard Model (SM) that can resolve the
gauge hierarchy problem. It can also provide a candidate for Dark Matter (DM). The
increase of centre-of-mass energy at the LHC from 8 to 13 TeV greatly extends the
mass reach for SUSY searches. Recent results of searches for direct stop pair
production, highlighting the zero-lepton channel analysis using 13.3fb-1 of 13 TeV
data collected with the ATLAS detector at the LHC, will be discussed. No significant
excess is observed over the SM background expectation and exclusion limits are set
on the stop and neutralino masses. Limits are also set in terms of simplified
models describing the associated production of DM with top quark pairs through a
(pseudo)scalar mediator.