The interacting boson-fermion model has become in recent years the standard model for the description of atomic nuclei with an odd number of protons and/or neutrons. This book describes the mathematical framework on which the interacting boson-fermion model is built and presents applications to a variety of situations encountered in nuclei. The book addresses both the analytical and the numerical aspects of the problem. The analytical aspect requires the introduction of rather complex group theoretic methods, including the use of graded (or super) Lie algebras. The first (and so far only) example of supersymmetry occurring in nature is also discussed. The book is the first comprehensive treatment of the subject and will appeal to both theoretical and experimental physicists. The large number of explicit formulas for level energies, electromagnetic transition rates and intensities of transfer reactions presented in the book provide a simple but detailed way to analyse experimental data. This book can also be used as a textbook for advanced graduate students.

This book gives an account of the properties of the interacting boson model.

The fundamental model of nuclear structure is the shell model. However, its application has been limited to light nuclei (up to the sd shell) or heavier nuclei with only a few valence nucleons outside closed shells. Its application beyond these limits has been prohibited so far by the largescale of the calculations involved. For the description of nuclei beyond the sd shell having several valence nucleons the introduction of collective models becomes necessary.The first comprehensive phenomenological model of nuclear structure was the geometric collective model of A. Bohr and B.R. Mottelson. An alternative approach was proposed in 1974 by A. Arima and F. Iachello, known as the Interacting Boson Model. This model, which uses group theoretical techniquesin the description of nuclear collective properties, has the advantage of relative simplicity, allowing for detailed calculations of the properties of even medium and heavy nuclei which cannot be reached by the shell model yet. Several extensions and generalizations of the model have appeared overthe last decade. Algebraic descriptions for the effects of clustering, permanent octupole deformation, and giant resonances have also been given. For the description of odd nuclei the Interacting Boson-Fermion Model has been introduced, and nuclear supersymmetries associated with it have beenanalysed.The present text is designed to provide physicists with an accessible introduction to the subject.

During the week of June 6-9, 1978, a group of 36 physicists from 15 countries met in Erice, Sicily, for the first specialized seminar on "Interacting Bosons in Nuclear Physics". The countries represented were Argentina, Belgium, Denmark, Finland, France, the Federal Republic of Germany, Israel, Italy, Japan, the Netherlands, Poland, Sweden, the United Kingdom, the United States of America and Yugoslavia. The Seminar was sponsored by the Italian Ministry of Public Education (MPI), the Italian Ministry of Scientific and Technological Research (MRST), the North Atlantic Treaty Organiza tion (NATO) and the Regional Sicilian Government (ERS). The purpose of the Seminar was to discuss the present status of the Interacting Boson Model both from the theoretical and experi mental point of view. Some of the lectures presented in this book summarize particular aspects of the model and are based on previously published work (F. Iachello, R.F. Casten, Z. Sujkowski, L. Hassel gren, H. Emling, I. Talmi, T. Otsuka, J. McGrory, A.E.L. Dieperink and A. Arima). Others are entirely new. In particular, the lec tures of O. Scholten and A. Gelberg and V. Kaup present the first extensive set of calculations based on the proton-neutron boson model, while the lecture of J.N. Ginocchio describes a fermion model with properties identical to those of the interacting boson model. Also new are the le~tures of D.R. Bes, R.A. Broglia and P.F.