1962

Ph.D

University of Madras

This thesis is devoted to the study of some topics in the strong and weak interactions of elementary particles with special emphasis on the application of techniques in Dispersion relations, and Symmetry Principle in the field of Quantum Field Theory. The thesis comprises of three parts, viz., (i) Strong interactions ( by non perturbative methods), (ii) weak interactions, with special emphasis on dispersion relations and symmetry principles and (iii) concept of causality in deterministic, stochastic and quantum mechanical processes. It is found worthwhile to discuss the causal connection between events which in turn necessitates the clarification of an event in the quantum mechanical description. A point of view is stressed that the integrand of the S-matrix represents the amplitude for a pattern of events though these events are not realizable or observable in a scattering process. It is found useful to divide such events into two classes, Causative and resultant. The procedure of determining amplitudes consists in connecting a causative event to its corresponding resultant or vice-versa. It is the essence of Feynman formalism brings out the role of causality in a scattering process in a perspicuous manner. A combinatorial problem relating to Feynman diagrams is posed and solved.