Search for Scalar Top Admixture in the ttbar Lepton+Jets Channel at D0

Abstract

A search has been performed for scalar top quark pair production in the lepton+jets channel in ~1 fb^(-1) of data. Kinematic differences between the exotic stop-stopbar and the dominant ttbar process are used to separate the two possible contributions. For scalar top quark masses of 145-175 GeV and chargino masses of 105-135 GeV we obtain upper cross section limits at 95% confidence level for stop-stopbar production that are a factor of ~7-12 higher than expected for the Minimal Supersymmetric Standard Model (MSSM).