Present Status of the Interacting Boson Model

Abstract

The purpose of this meeting is to discuss the scope and limitations of the interacting boson model1 which has been introduced recently in order to describe collective low-lying states in medium and heavy-mass nuclei. In my talk, I will summarize the present status of the model referring to the following talks for more detailed and complete expositions. It seems appropriate to divide the talk in two parts in the first part, I will discuss the interacting boson model, as a tool to classify and describe collective states in nuclei; in the second part, I will discuss the interacting boson approximation in which one tries to derive the model as an approximation scheme to the shell model, thus providing a microscopic description of the collective states. While at present the first part may be, to a good extent, considered concluded, in the sense that all possible solutions have been investigated, the second part is still in its infant stage, and it may require several years before a fully microscopic theory will be preserved.