An enhancement of neutral tc transitions in the model of dynamical breaking of the electroweak symmetry

Abstract

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.