Dynamical symmetry breaking by a top quark condensate in the standard model

Abstract

We consider the possibility that dynamical symmetry breaking is driven by massive scalar exchange. It is shown that after symmetry breaking the original scalar field has a light component and must be kept in the low-energy effective lagrangian. A method of regularisation is developed to allow for the derivation of a gap equation applicable in this case. The analysis is applied to the standard model for the case of positive scalar mass squared and large top quark Yukawa coupling. The spectrum of the model is determined and implications for the masses of the top quark and Higgs boson are considered.