  There is a question about the identity of the top quark. Is it the top quark
of the Standard Model (SM) with electric charge 2/3 or is it an exotic quark
with charge -4/3? An exotic quark has been proposed by D. Chang et
al.\cite{hep-ph/9810531, hep-ph/9805273}. This analysis will use the standard
CDF run II dilepton sample. The key ingredients of this analysis are the
correct pairing of the lepton and b-jet, the determination of the charge of the
b-jet. The analysis proceeds by using a binomial distribution and is formulated
so that rejecting one hypothesis means support for the other hypothesis.
