The ψ-resonances

Abstract

The main idea of this thesis is to review the ψ - resonances. The past two years since the discovery of ψ -particles at SPEAR and BML have been the most exhilarating of particle physics in many years. In the following pages we try to summarize the great amount of information which has been gathered in this short period. In Chapter one, we summarize the experimental data about the ψ- particles, i.e. their masses, lifetimes and decay modes. We have also presented a summary of the known spectrum of the ψ - family. In Chapter two, we review briefly SU(3) group and quark model. Then we discuss the need for the extension of SU(3) group to SU(^), and finally we consider the classification of elementary particles in SU(4) group and the introduction of charmed particles. In Chapter three, the idea of interpretation off ψ - particles as bound states of charmed quarks and antlquarks (cc) has been presented. In Chapter four, some other interpretations, which have been advanced for the new resonances, are discussed. Two sections are devoted to the phenomenology of ψ - particles In Han-Nambu colour scheme and in Harari's model and some other models such as the weak boson interpretation and the Iwasaki's model are discussed briefly in this chapter.