Brueckner-AMD Method and Its Applications to Light Nuclei

Abstract

We propose a new approach employing the Brueckner-AMD in which the G-matrix is calculated using the antisymmetrized molecular dynamics (AMD). Its applications to some light nuclei are demonstrated, and the high reliability of the description of the shell and cluster structures is discussed. In the conventional approach employing the G-matrix for the study of nuclear matter or the shell model, the constructed G-matrix is used to reproduce effective interactions. Therefore, the effective interactions are valid only in the model space. It is desirable for the model space to be as large as possible, but for practical reasons, a finite dimensional space is used. For this reason, the effective interaction is model dependent, 1) and one must accept the limits of its applicability. The conventional shell model calculations have failed in the description of nuclear cluster states, which are observed in the excited states around cluster thresholds. By contrast, the cluster model has been shown to provide a successful description of these states. Recent developments of the cluster model based on the antisymmetrized molecular dynamics (AMD) 2) have led to success in reproducing the various kinds of cluster structures of excited states, in addition to the shell model structure of the ground and low-lying states, without any assumption concerning cluster configurations. This result indicates that the functional space of AMD is very large; the wave functions of AMD can describe not only shell model configurations but also cluster configurations. However, to this time studies of AMD have been carried out without detailed investigations of the effective interactions. It is important to construct a framework of the G-matrix for AMD. In this letter, we propose a framework of the Brueckner-AMD to calculate the G-matrix for AMD. Since the pioneering cluster study of α + α, 3) there has been much interest in elucidating the role of the tensor force component resulting from the one-pion exchange potential (OPEP) in the α-cluster formation and the binding mechanism of the α-particle. 4) – 8) Study of the G-matrix has been carried out in association with the appearance of α-clustering and the cluster structures in the low-excitation [ (