Search for direct top squark pair production in final states with one isolated lepton, jets, and missing transverse momentum in sqrt(s) = 7 TeV pp collisions using 4.7 ifb of ATLAS data

A search is presented for direct top squark pair production in final states with one isolated electron or muon, jets, and missing transverse momentum in proton-proton collisions at a center-of-mass energy of 7~\TeV. The measurement is based on 4.7~\ifb\ of data collected with the ATLAS detector at the LHC. The top squarks are assumed to decay each to a top quark and the lightest supersymmetric particle (LSP). The data are found to be consistent with Standard Model expectations. Top squark masses between 230 and 440~\GeV\ are excluded at 95\% confidence for massless LSPs, and top squark masses around 400~\GeV\ are excluded for LSP masses up to 125~\GeV.