The Problem of Mass

Abstract

The quark-lepton mass problem and the ideas of mass protection are reviewed. The Multiple Point Principle is introduced and used within the Standard Model to predict the top quark and Higgs particle masses. We discuss the lightest family mass generation model, in which all the quark mixing angles are successfully expressed in terms of simple expressions involving quark mass ratios. The chiral family flavour symmetry of the family replicated gauge group model is shown to provide the mass protection needed to generate the hierarchical structure of the quark-lepton mass matrices.