This workshop held at the New England Center provided a timely opportunity for over 100 participants to gather in a unique environment and discuss the present status of the unification of strong and electroweak forces. One reason for the timeliness was perhaps that experiments of the seventies had already lent confirmation to the separate theories of strong and of electroweak forces, so that for the eighties it now seems especially compelling to attempt the grand unification of these two forces. Also, the planned experiments to search for proton decay and the new experiments which are suggestive, though not yet conclusive, of non-zero neutrino rest masses add further stimulus to the theory. Thus, the workshop provided an ideal forum for exchange of ideas amongst active physicists. The presentations at the workshop covered the present status of both theory and experiment with a strong interplay. Also, there were presentations from the discipline of astrophysics which is becoming very intertwined with that of high-energy physics especially when in the latter one is addressing energies and temperatures that were extant only in the first nanosecond of the universe. On experiment, we heard a comprehensive coverage of the four United States proton decay experiments. The Brookhaven-Irvine-Michigan experiment in the Morton Salt Mine at Fairport Harbor, Ohio was discussed by LARRY SULAK, while DAVID WINN talked on the Harvard-Purdue-Wisconsin effort in the Silver King Mine, Utah. MARVIN MARSHAK and RICHARD STEINBERG described respectively the Soudan Mine, Minnesot~ and the Homestake Mine, South Dakot~experiments.

Recently there has been rapid progress towards understanding the separate theories of the strong, weak and electromagnetic inter actions within the framework of the standard SU(3) x SU(2) x U(l) model. The purpose of the Second Workshop on Grand Unification was to discuss the physics beyond the standard model and the major topic was grand unified theories which unify the strong, weak and electromagnetic sectors. Grand unified theories are presently being used to calculate experimentally accessible quantities such as the proton lifetime and nucleon decay branching ratios. Meanwhile, experiments are currently being performed, and new, dedicated experiments mounted, to measure these quantities. Reports on these experimental and theoretical activities occupied much of the workshop. Furthermore, since grand unified theories allow one to extrapolate the behavior of the universe back to the first instants after the big bang, their cosmological implications and the constraints on these theories from cosmology were of great interest at the workshop. The conference opened with a keynote address by S. L. Glashow in which he discussed among other topics baryon minus lepton number conservation, neutrino masses and a neutrino-free universe. To maximize the interplay between theorists and experimentalists, theoretical and experimental talks were interleaved. An experimental highlight of the workshop was the presentation by S. Miyake of three candidate events for proton decay.

It has been sixteen years since the unification of electro Magnetism with the weak interactions was developed by Glashow, Salam, and Weinberg. Well before that proposal was fully confirmed by experiment, work began on unifying strong interactions with the electroweak. Now there is a growing effort to incorporate some theory of quantum gravity into the scheme. This enormous complex of theoreti cal and experimental efforts was the subject of the Fourth Workshop on Grand Unification held in Philadelphia and attended by over two hundred physicists. During the workshop, experimental and theoretical talks alternated as shown by the program summary on page 409. However, to display the logical scope of the workshop the proceedings are organized into five subject areas. Howard Georgi opened the workshop with a keynote address in which he reminds us of some of the simple properties of the particle spectrum that have not yet been understood. The first subject area, and also the largest, is proton decay and underground physics. This is introduced by ~Jill iam r1arciano' s review of the SU(5) predictions with particular attention paid to the theoretical uncertainties. Spokesmen for the major underground experiments present current results on proton decay, nn oscillations, and magnetic monopole flux: B. V. Sreekantan for the Kolar gold field experiment after 1. 9 years of operation, Earl Peterson for the Soudan detector after 0. 55 years, and Bruce Cortez for the rr'lB detector after 0. 22 years.

This workshop held at the University of North Carolina was in the series which started with meetings in the University of New Hampshire (April 1980) and the University of Michigan (April 1981). More than one hundred participants congregated in the Carolina Inn in April 1982 to discuss the status of grand unified theories and their connection to experiment. The spring foliage of Chapel Hill provided a beautiful back-drop to this Third Workshop on Grand Unification. As mentioned in the first talk herein, these three workshops have heard of indications, respectively, of neutrino oscillations, proton decay and a magnetic monopole. Since all three experimental reports remain unconfirmed, grand unifiers must wait expectantly and patiently. These proceedings preserve faithfully the ordering of the workshop talks which followed the tradition of alternation between theory and experiment. Only our introduction will segregate them. The experimental presentations mainly concerned proton decay and massive neutrinos. Four U.S. proton decay experiments were reported: the Brookhaven Irvine-Michigan experiment in the Morton Salt Mine at Fairport Harbor, Ohio was described by WILLIAM KROPP, and ROBERT MORSE represented the Harvard-Purdue-Wisconsin group in the Silver King Mine, Utah. The Homestake Mine, South Dakota and Soudan Mine, Minnesota, experiments were reported respectively by RICHARD STEINBERG and DAVID AYRES, the latter providing also a survey of future U.S. experiments.

This book covers the present status of art of grand unification with and without supersymmetry (gravity), including cosmological consequences. It is addressed to graduate students and researchers interested in this fastly developing field. But without necessarily any previous experience, however, at least some parts of the book and, in particular, those concerning the most recent developments, are of interest to actively involved researchers in the field.

High Energy Physics and Nuclear Structure covers the proceedings of the Ninth International Conference on High Energy Physics and Nuclear Structure, held in Versailles on July 6-10, 1981. The book focuses on the processes, reactions, and methodologies involved in high energy physics and nuclear structure. The selection first offers information on experiments on antinucleon-nucleon, baryonium, nucleon-nucleon, and dibaryons and the quark model pion and the goldstone pion. Discussions focus on antinucleon-nucleon and baryonium, nucleon-nucleon and dibaryon, and spontaneous breaking of chiral symmetry. The text also ponders on quarks and nuclei, multiquark resonant states, and electron scattering from complex nuclei. The publication elaborates on electromagnetic interactions on light nuclei, electromagnetic interactions with nuclei at high momentum transfer, and inelastic electron scattering at low energy. The book also touches on the dynamics of hadron nucleus interactions, hypernuclei and interactions of kaons with nuclei, and pion-nucleus scattering theory. The selection is a dependable reference for readers interested in high energy structure and nuclear physics.

We are now closer than ever to the fundamental goal of physics of understanding all physical phenomena as the inevitable consequences of few simple principles. The grand unified theory of the strong, weak and electromagnetic interactions has, among other things, explained the quantization of charge, determined the magnitude of the neutral current, and had dramatic impact on cosmology. This book is designed to bring interested students and researchers rapidly up to the point where they can contribute to this exciting field. A substantial text provides a review of the subject. In particular, several chapters are devoted to cosmology and the theory of galaxy formation. A selection of original papers is reprinted. A brief review of group theory is also provided. It is a must for all students and researchers in the field.

The papers contained in this volume are invited lec tures presented at the 21st "Universit~tswochen fUr Kern physik" in Schladming in February 1982. To consider electro magnetic and weak interactions as manifestations of a single theory is a standpoint, which is generally accepted by now. The goal of the school was to outline the present state of this unified theory and to discuss possible future developments. Thanks to the generous support provided by the Austrian Ministry of Science and Research, the Styrian Government and other sponsors, it was again possible to invite experts in the field as lecturers. The lecture notes have been reexamined by the authors and are now published in their final form to enable a larger number of physicists to profit from them. Since the lectures are already quite voluminous, we have decided to restrict the publication to the lectures themselves and omit all seminars, interesting as they were, as well as all details connected with the meeting. It is a pleasure to thank all the lecturers for their efforts, making it possible to speed up publication. Thanks are also due to L. Pittner for organisation and proof-reading as well as to Mrs. Krenn and Mrs. Neuhold for the careful typing of the papers. H. Mitter Acta Physica Austriaca, Suppl. XXIV, 3-62 (1982) © by Springer-Verlag 1982 INTRODUCTION TO GAUGE THEORIES OF ELECTRO + WEAK INTERACTIONS by G. ECKER Institut fUr Theoretische Physik Universitat Wien, Austria TABLE OF CONTENTS I