The Brueckner theory of nuclear structure

Abstract

The object of the Brueckner theory is to calculate the properties of atomic nuclei from a knowledge of the forces which act between nucleons in free space. The method involves constructing a nuclear model having the same energy as the nucleus, and it also gives a relation between the nuclear model and the actual nucleus which can be used to investigate detailed aspects of the nucleus in circumstances where the model is insufficient. Previous papers on the Brueckner theory have used a formalism applicable only to an infinite medium of nuclear matter and this has involved some inconsistencies. The present paper establishes the theory in a form which applies to a nucleus of finite size and therefore provides a basis for calculating from first principles the properties of an actual nucleus. The nuclear model on which the method is based is closely related to the nuclear shell model and is determined by a set of coupled self-consistent equations which take into account the strong short-range character of nuclear forces. These self-consistent equations have also been derived by H. A. Bethe who describes methods of solving them in a paper to be published in the Physical Review. The present paper concentrates on the derivation and meaning of the equations for the model, on their relation to a self-consistent variational procedure, on the relation between the model and the nucleus and on discussing correction terms neglected in the construction of the model. The justification of the theory depends primarily on the operation of the exclusion principle between nucleons, but it also involves a physical assumption related to the absence of clustering in the nucleus.