We present a search for the lightest supersymmetric partner of the top quark in proton-antiproton collisions at a center-of-mass energy $\sqrt{s}=1.96\mathrm{TeV}$. This search was conducted within the framework of the $R$ parity conserving minimal supersymmetric extension of the standard model, assuming the stop decays dominantly to a lepton, a sneutrino, and a bottom quark. We searched for events with two oppositely-charged leptons, at least one jet, and missing transverse energy in a data sample corresponding to an integrated luminosity of $1{\mathrm{fb}}^{-1}$ collected by the Collider Detector at Fermilab experiment. No significant evidence of a stop quark signal was found. Exclusion limits at 95% confidence level in the stop quark versus sneutrino mass plane are set. Stop quark masses up to $180\mathrm{GeV}/c^2$ are excluded for sneutrino masses around $45\mathrm{GeV}/c^2$, and sneutrino masses up to $116\mathrm{GeV}/c^2$ are excluded for stop quark masses around $150\mathrm{GeV}/c^2$.

• Received 3 September 2010

DOI:https://doi.org/10.1103/PhysRevD.82.092001