We attempt to obtain a unified description of the bound and unbound states of multivalence nucleons of a core system in the framework of the cluster-orbital shell model (COSM). In this framework, the interaction between the core and a valence nucleon (the core-N interaction) is treated microscopically, and the changes in both the core structure and the core-N interaction are discussed on the same basis. Furthermore, the center-of-mass motion of every nucleon is completely eliminated, and higher shell configurations, including unbound continuum components, are appropriately taken into account by applying a stochastic variational approach. To examine the reliability of this approach and to discuss how the dynamics of the core reflects to the total system, we study oxygen isotopes and $N=8$ isotones, which are described by ${}^{16}\mathrm{O}$ + Xn and ${}^{16}\mathrm{O}$ + Xp models, respectively.

• Received 1 October 2005

DOI:https://doi.org/10.1103/PhysRevC.73.034318