Alpha-Cluster plus¹⁶O-Core Model for²⁰Ne and Neighboring Nuclei

Abstract

A possibility of a-cluster structure in nuclei around 20 Ne is examined in terms of a model based on the assumption of weak coupling between an tit cluster and an 16 0 core. The model treats dynamically the coupling of a-160 relative motion with a particle (j.J)-and a hole (h)motion in an average nuclear field of 1 60. The K'lt=o-lrotational band of ZONe (a+160) is plausibly explained with an effective tit-16 0 potential having repulsive core and state-dependent attractive well. The low-lying anomalous-parity levels of HlF (a+ 1 60+h) and the ground rotational band of 21Ne (a+16Q +p) are reasonably understood in terms of an effective nucleon-a potential with the essential features of the potential in free space. The hole and particle are treated in th weak-and strong-coupling schemes, respectively. The K7(=2rotational band of 20Ne* (a+160+p+h) is well interpreted in the strong-coupling scheme for the p-h pair. In conclusion, certain successes of the model seem to suggest an importance of a-like four-hody correlation or molecular aspect in light nuclei. I. Introduction Many attempts have been made to explain various properties of light nuclei in terms of the shell model descriptions, namely the standard shell-model calculations,2> the SU 3 model, 3 > the method of deformed orbitals 4 > and so on. These descriptions are essentially based on the average nuclear field and the two-body correlation.