Search for the supersymmetric partner of the top quark in ppbar collisions at sqrt(s) = 1.96 TeV

TL;DR

This paper reports a search for the supersymmetric partner of the top quark in proton-antiproton collisions at 1.96 TeV, setting exclusion limits on their masses due to no observed signal.

Contribution

First search for the stop quark decaying to a lepton, sneutrino, and bottom quark in proton-antiproton collisions at this energy.

Findings

Excluded stop masses up to 180 GeV/c^2 for certain sneutrino masses.

Excluded sneutrino masses up to 116 GeV/c^2 for certain stop masses.

No significant evidence of stop quark signal found.

Abstract

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 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 1fb^-1 collected by the CDF 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 GeV/c^2 are excluded for sneutrino masses around 45 GeV/c^2, and sneutrino masses up to 116 GeV/c^2 are excluded for stop quark masses around 150 GeV/c^2.