Exclusion of exotic top-like quarks with -4/3 electric charge using jet-charge tagging in single-lepton ttbar events at CDF

摘要

We report on a measurement of the top-quark electric charge in ttbar eventsin which one W boson originating from the top-quark pair decays into leptonsand the other into hadrons. The event sample was collected by the CDF IIdetector in sqrt(s)=1.96 TeV proton-antiproton collisions and corresponds to5.6 fb^(-1). We find the data to be consistent with the standard model andexclude the existence of an exotic quark with -4/3 electric charge and mass ofthe conventional top quark at the 99% confidence level.