First results on top-quark from ATLAS

The search for first top pair candidate events and the related preliminary background studies using data-driven techniques are reported in about 300 inverse nb of sqrt(s)=7 TeVproton-proton collisions data delivered by the Large Hadron Collider (LHC) and collected with the ATLAS detector. Selected events are characterized by the presence of charged high-pT, isolated lepton(s), high jet multiplicity, jet(s) identified as originating from b-quarks by a secondary vertex tagger algorithm, and missing transverse energy, and reveal kinematics properties consistent with top pair production.