Measurement of the top quark charge at CDF

Since the discovery of the top quark at Fermilab in 1995, the CDF collaboration has studied and measured many of its properties. One of the fundamental properties is the charge. The Standard Model predicts the top quark charge to be +2/3, but there is also an alternative theory arguing that the observed quark is a fourth generation quark with charge -4/3. We present the results of the top quark charge measurement via its decay products. A charge track weighting technique has been used to determine the b-jet charge and the CDF kinematic fitter has been exploited to determine the lepton - b-jet assignment in the lepton+jet case and an invariant mass cut in the dilepton topology.