Sakurai J.J. Invariance Principles and Elementary Particles

Princeton University Press Princeton, NEW JERSEY 1964, 326 p.
The purpose of the present monograph is to discuss various elementary
particle phenomena that can be understood from a few general principles
based on in variance or symmetry considerations. I have tried to strike a
reasonable balance among fundamental concepts, applications to well-
known problems, and implications to problems in the twilight zone. A
purely formal and axiomatic approach is avoided as much as possible, and
emphasis is placed on physical and empirical aspects of the various
in variance principles. Since elementary particle physics today is in a
confused state, it is not surprising that certain parts of the monograph seem
somewhat disorganized; it is written in such a way that there will still be
room for new ideas.
The monograph is based on a graduate course given at the University of
Chicago in the Spring quarter of 1959 (needless to say, numerous
developments since that time in this rapidly growing field have been incorporated).
The students in the original course were assumed to be familiar with
elementary field theory including the quantization of free fields and co-
variant calculational techniques. However, the monograph is written in
such a way that the reader who is unfamiliar with field theory may gain a
great deal even if he skips certain difficult sections that require a firm
understanding of field theory. For instance, it may be read profitably even
if all but the earlier sections of Chapter 5 and the entire Chapter 6 are
omitted. I should like to emphasize that many symmetry arguments can
be understood on the phenomenological level; it is unfortunate that a
number of experimentalists as well as theoreticians hold the erroneous
view that one must know field theory to understand simple symmetry
arguments.
In general, I have tried to make this work readable for people with
different backgrounds—serious graduate students of elementary particle
theory, low energy physicists who want to become acquainted with high
energy physics, active experimentalists in particle physics who wish to
gain insight into theoretical problems, etc. In my past contacts with various
people, I have found that certain concepts in elementary particle physics
are tacitly assumed in the current journals by the ''experts," but are not
adequately treated in existing textbooks. It is hoped that the present
monograph will serve to fill in this gap which is becoming increasingly
serious as it widens.
Sections of the monograph are based on lecture notes taken by Frank
Chilton and P. Schlein. The help of S. G. Eckstein and S. F. Tuan is also
appreciated. I would like to take this opportunity to emphasize that,
without their untiring work and numerous suggestions, the present monograph
would never have materialized.