Microscopic α-cluster model for 12C and 16O based on antisymmetrized molecular dynamics. Consistent understanding of the binding energies of 12C and 16O

In many previous calculations within microscopic models, the binding energy difference between 12C and 16O nuclei has been too large compared with the experimental data, and it has not been possible to describe these nuclei reasonably by the same effective interaction simultaneously. In this paper, we apply the Nα-cluster model so as to clarify what is the most essential problem in the description of 12C and 16O by using a very large functional space and various effective interactions. This procedure is carried out by combining frameworks of the constraint cooling method introduced in Antisymmetrized Molecular Dynamics (AMD) and generator coordinate method (GCM). The resultant energy levels of 16O show that various effective interactions give the second 0+ state of 16O just around the 12C+α threshold energy. This result agrees with the picture of the Ikeda diagram. However, even if we use some density dependent interactions, the binding energy difference between 12C and 16O cannot be remarkably improved. (author)