Gamow states and continua in the cluster-orbital shell model approach

Importance of the unbound states in loosely bound systems by comparing to the stable nuclei is investigated. We use the cluster-orbital shell model (COSM) approach and expand the wave function using the complete set of the single-particle states. The completeness relation is constructed by the Berggren metrics, which includes bound, resonant and anti-bound states, and continua. We precisely investigated such the contributions of the resonant states (Gamow states) and continua in the helium isotopes and compare them those obtained by the Gamow shell model.