An enhancement of neutral tc transitions in the model of dynamical   breaking of the electroweak symmetry
  The problem of possible deviations from the Standard Model is considered in the framework of a variant of dynamical electroweak symmetry breaking. It comes clear, that the parameters of the theory, being obtained earlier and describing deviations from SM in Z --> \bar b b decay, are also consistent with the existence of a nontrivial solution for vertex \bar t (Z,\gamma) c. The occurrence of this solution leads to a significant enhancement in neutral flavor changing transition t --> c. The intensity of this transition is connected with the c-quark mass, that leads to estimates of probabilities of exotic decays t --> c (Z,\gamma) (few %) and of the cross-section of a single t-quark production in process e^+e^- --> t \bar c at LEP2 (around 0.03 pb at \sqrt{s} = 190 GeV). The model is shown to be consistent with the totality of the existing data; the predictions allow its unambiguous check. 
B. A. Arbuzov and M. Yu. Osipov