Abstract:

A new class of models describing the quark mass hierarchy is discussed. In this class, the dynamics primarily responsible for electroweak symmetry breaking (EWSB)  leads to the mass spectrum of quarks with no (or weak) isospin violation. Moreover, the values of these masses are of the order of the observed masses of the down-type quarks. Then, strong (although subcritical) horizontal diagonal interactions for the t quark plus horizontal flavor-changing neutral interactions between different families lead to a realistic quark mass spectrum. In thisscenario, composite Higgs bosons occur. Their properties are described in detail in a model with the dynamical EWSB providing by the fourth family fermions.