Symmetry schemes for elementary particles

In this dissertation an attempt has "been made to distinguish between results "based on a relativistic combination of spin and SU(3) internal symmetry and one of spin and U(2) internal symmetry, An attempt has also been made to allow spin-dependent modifications to these theories so that the results are less vague in that the correct masses of particles appear in the theories. To facilitate understanding of this subject the early part of the thesis is devoted to some aspects of group theory required in later sections. As a further introductory consideration we consider the internal group SU(3) and its non-relativistic combination with spin SU(6)