Abstract
A search for direct pair production of supersymmetric top squarks (t(1)) is presented, assuming the t(1) decays into a top quark and the lightest supersymmetric particle, _(1)(0), and that both top quarks decay to purely hadronic final states. A total of 16 (4) events are observed compared to a predicted standard model background of 13.5(-3.6)(+3.7)(4.4(-1.3)(+1.7)) events in two signal regions based on _Ldt = 4.7 fb(-1) of pp collision data taken at sqrt[s] = 7 TeV with the ATLAS detector at the LHC. An exclusion region in the t(1) versus _(1)(0) mass plane is evaluated: 370<m(t)(1)}<465 GeV is excluded for m(_)(1)(0) ~ 0 GeV while m(t)(1) = 445 GeV is excluded for m(_)(1)(0) _ 50 GeV.