Dynamical Generation of Fermion Mass Hierarchy

Abstract

We describe a simple mechanism to break electroweak symmetry dynamically as well as to generate a large fermion mass hierarchy. The mechanism is displayed within the framework of a simple left-right symmetric model. The model has exact horizontal symmetry which is broken dynamically giving rise to the mixing angles as well as to the fermion masses. The light fermions acquire masses by exchange of the charged gauge bosons, which is possible in the case of a left-right symmetric gauge group. We display a simple mechanism to break the left-right symmetry. The stability of the horizontal symmetry breaking solution is also discussed. We argue that if the gauge bosons are massive then for a certain range of the gauge couplings the horizontal symmetry breaking solution may be locally stable. We discuss some phenomenological difficulties, in particular the question of unobserved Goldstone bosons, that arise within the present model.