Top quark pair production at a linear collider in the presence of an anomalous Wtb coupling

Angular distributions of a mu+ and a b-quark resulting from the decay of a top quark produced at the e+e- linear collider with an unpolarized and a 100% longitudinally polarized electron beam are presented. The results of the standard model are compared with the results obtained in the presence of the anomalous Wtb coupling.