The primary goal of this text is pedagogical; providing a clear, logical, in-depth, and unifying treatment of many diverse aspects of modern nuclear theory ranging from the non-relativistic many-body problem to the standard model of the strong, electromagnetic, and weak interactions. Four key topics are emphasized in this text: basic nuclear structure, the relativistic nuclear many-body problem, strong-coupling QCD, and electroweak interactions with nuclei. The text is designed to provide graduate students with a basic level of understanding of modern nuclear physics so that they in turn can explore the scientific frontiers.

From 23 July to 10 August 1977 a group of 125 physicists from 72 laboratories of 20 countries met in Erice to attend the 15th Course of the International School of Subnuclear Physics. The countries represented at the School were: Belgium, Bulgaria, Denmark, Federal Republic of Germany, Finland, France, Hungary, Ireland, Israel, Italy, Japan, the Netherlands, Norway, Poland, Sweden, Switzerland, the United Kingdom, the United States of America and Venezuela. The School was sponsored by the Italian Ministry of Public Education (MPI), the Italian Ministry of Scientific and Technologi cal Research (MRST) , the North Atlantic Treaty Organization (NATO), the Regional Sicilian Government (ERS) and the Heizmann Institute of Science. The School was very exciting due to the impressive number of frontier problems which were discussed. Being the 15th year of the School, it was decided to review all outstanding "Whys". At various stages of my work I have enjoyed the collaboration of many friends whose contributions have been extremely important for the School and are highly appreciated. I would like to thank Dr.A. Gabriele, Ms.S. McGarry, Mr. and Mrs. S. Newman, Ms.P. Savalli and Ms.M. Zaini for the general scientific and administrative work. Finally, I would like to thank most warmly all those ~n Erice, Bologna and Geneva who helped me on so many occasions and to whom I feel very much indebted.

This book is a useful and accessible introduction to symmetry principles in particle physics. Concepts of group theory are clearly explained and their applications to subnuclear physics brought up to date. The book begins with introductions to both the types of symmetries known in physics and to group theory and representation theory. Successive chapters deal with the symmetric groups and their Young diagrams, braid groups, Lie groups and algebras, Cartan's classification of semi-simple groups, and the Lie groups most used in physics are treated in detail. Gauge groups are discussed, and applications to elementary particle physics and multiquark systems introduced throughout the book where appropriate. Many worked examples are also included. There is a growing interest in the quark structure of hadrons and in theories of particle interactions based on the principle of gauge symmetries. Students and researchers on theoretical physics will make great strides in their work with the ideas and applications found here.

During July and August of 1976 a group of 90 physicists from 56 laboratories in 21 countries met in Erice for the 14th Course of the International School of Subnuclear Physics. The countries represented were Argentina, Australia, Austria, Belgium, Denmark, the Federal Republic of Germany, France, the German Democratic Republic, Greece, Israel, Italy, Japan, Mexico, Nigeria, Norway, Sweden, the United Kingdom, the United States of America, Vietnam, and Yugoslavia. The School was sponsored by the Italian Ministry of Public Education (MPI), the Italian Ministry of Scientific and Technological Research (MRST), the North Atlantic Treaty Organi zation (NATO), the Regional Sicilian Government (ERS), and the Weizmann Institute of Science. The program of the School was mainly devoted to the elucida tion and discussion of the progress achieved in the theoretical and experimental understanding of the fundamental constituents of matter. On the theoretical front we had a series of remarkable lecturers (C. N. Yang, S. Weinberg, G. C. Wick) attempting a description of finite size particles. Another group of lecturers covered such topics as the understanding of the new particles (H. J. Lipkin), whether or not jets really exist (E. Lillethun), and the unexpected A-dependence of massive dileptons produced in high-energy proton- nucleus collisions (J. W. Cronin). Two other outstanding questions were covered by E. Leader and G. Preparata respectively: whether strong interactions are still within the Regge framework, and if it is really possible to master strong interactions. A. J. S.

The notion that fundamental equations governing the motions of physical systems are invariant under the time reversal transformation (T) has been an important, but often subliminal, element in the development of theoretical physics. It serves as a powerful and useful tool in analyzing the structure of matter at all scales, from gases and condensed matter to subnuclear physics and the quantum theory of fields. The assumption of invariance under T was called into question, however, by the 1964 discovery that a closely related assumption, that of CP invariance (where C is charge conjugation and P is space inversion), is violated in the decay of neutral K mesons. In The Physics of Time Reversal, Robert G. Sachs comprehensively treats the role of the transformation T, both as a tool for analyzing the structure of matter and as a field of fundamental research relating to CP violation. For this purpose he reformulates the definitions of T, P, and C so as to avoid subliminal assumptions of invariance. He summarizes the standard phenomenology of CP violation in the K-meson system and addresses the question of the mysterious origin of CP violation. Using simple examples based on the standard quark model, Sachs summarizes and illustrates how these phenomenological methods can be extended to analysis of future experiments on heavy mesons. He notes that his reformulated approach to conventional quantum field theory leads to new questions about the meaning of the transformations in the context of recent theoretical developments such as non-Abelian gauge theories, and he suggests ways in which these questions may lead to new directions of research.

Annotation Focuses on the theoretical investigation of several basic unity issues.

For the Galvani Bicentenary Celebrations, the University of Bologna and its Academy of Sciences singled out subnuclear physics as the field of scientific research to be associated with this important event, as it would best illustrate, for the new generation of students, the challenge inherent in fundamental sciences. Subnuclear physics has represented, ever since it was born, the new frontiers of Galilean science. In his opening lecture delivered on the first day of the new academic year, Professor Antonino Zichichi analytically reviewed the basic conceptual developments and main discoveries achieved in subnuclear physics since its birth in the 20th century. Given the importance of this field of fundamental research, Professor Zichichi was invited to expand the contents of his lecture into a book, and the outcome is this volume.

The book provides theoretical and phenomenological insights on the structure of matter, presenting concepts and features of elementary particle physics and fundamental aspects of nuclear physics. Starting with the basics (nomenclature, classification, acceleration techniques, detection of elementary particles), the properties of fundamental interactions (electromagnetic, weak and strong) are introduced with a mathematical formalism suited to undergraduate students. Some experimental results (the discovery of neutral currents and of the W± and Z0 bosons; the quark structure observed using deep inelastic scattering experiments) show the necessity of an evolution of the formalism. This motivates a more detailed description of the weak and strong interactions, of the Standard Model of the microcosm with its experimental tests, and of the Higgs mechanism. The open problems in the Standard Model of the microcosm and macrocosm are presented at the end of the book.

The second volume of this authoritative work traces the material outlined in the first, but in far greater detail and with a much higher degree of sophistication. The authors begin with the theory of the electromagnetic interaction, and then consider hadronic structure, exploring the accuracy of the quark model by examining the excited states of baryons and mesons. They introduce the color variable as a prelude to the development of quantum chromodynamics, the theory of the strong interaction, and go on to discuss the electroweak interaction--the broken symmetry of which they explain by the Higgs mechanism--and conclude with a consideration of grand unification theories.