Search for the supersymmetric partner of the top quark in dilepton events produced in proton-antiproton collisions at center of mass energies equal to 1.8 TeV

Abstract

Supersymmetric partners of top quarks, stops, will be pair produced at the Fermi National Accelerator Laboratory in proton-antiproton collisions at a center-of-mass energy [special characters omitted] = 1.8 TeV if kinematically accessible. Within the framework of the Minimal Supersymmetric extension of the Standard Model, the stop quarks are assumed to decay into a lepton, a bottom quark and a supersymmetric neutrino, sneutrino. Thus the experimental signature of stop presence in the data would be two opposite electric charge leptons, hadronic jets and substantial energy imbalance in the detector due to the escaping, undetected sneutrinos. We searched a total of [special characters omitted] = 107.2 pb−1 of data collected by the Collider Detector at Fermilab experiment. No evidence of a stop signal has been found which allows us to calculate a 95% confidence level upper limit on the number of stop-originated events in the data of this size. We have translated this into a 95% confidence level exclusion region in the stop versus sneutrino mass plane