Scattering, Reactions And Decay In Nonrelativistic Quantum Mechanics

This monograph is intended mainly for postgraduate students and beginning theoretical physicists. Its aim is to fill the gap between standard text-books in quantum mechanics, on the one hand, and advanced-level books and periodical articles in the theory of quantized fields, on the other. Traditional courses in quantum mechanics mostly deal with general principles and the theory of stationary states. Particular problems of scattering theory, unstable states, and multichannel processes are generally treated in greatly condensed form, so that the student cannot acquire sufficient knowledge and techniques for independent work in this field. On the other hand, noninitiates embarking on a course in the theory of quantized fields and the closely related relativistic quantum mechanics have to fight their way through a jungle of unfamiliar concepts associated with Lorentz invariance, causality, mass and charge renormalization, and introduction of particle creation processes, In writing this book, we started with the premise that renormalization and creation problems can be studied in the nonrelativistic approximation, which is much more meaningful to the beginner. The reader will find here a detailed treatment of the theory of scattering and the -matrix, will learn how to work with a continuum of states, and familiarize himself with the theory of unstable particles, A substantial part of the book is based on the original researches of the authors. This includes the problem of scattering amplitude singularities when new channels are opened, the theory of unstable particles, the lifetime of intermediate states in scattering, a new formulation of the Lee model, nonrelativistic treatment of particle creation and nonconser- vation of parity. The choice of material was thus of necess