Nonlocalized clustering in O-18

The low-lying states (J(p) = 0(+), 2(+), and 4(+)) of O-18 system are investigated by using the microscopic Generator Coordinate Method (GCM)-Brink wave functions, in which one simple picture of O-16 + (2)n structure is assumed for investigating the character of relative motion of the core O-16 and the assumed dineutron cluster. By calculating the squared overlap between the GCM-Brink wave functions and the angular-momentum-projected TohsakiHoriuchi-Schuck-Ropke (THSR) wave functions in a simple O-18 (O-16 + (2)n) model, it is found that the single THSR wave functions characterizing the nonlocalized clustering are almost equivalent to the corresponding GCM-Brink wave functions. The results indicate that the concept of nonlocalized clustering can be extended even in the more-shell model-like states in nuclei.