Description of A=22 nuclei in the collective pair approximation

The structure of A = 22 nuclei has been studied in the framework of the collective pair approximation. The collective pairs determined by diagonalizing the Hamiltonian in the space of two nucleons with respect to the closed core of (16)O have been considered as building blocks to expand the truncated shell-model space in terms of three pairs. It is shown that the low-lying, shell-model spectrum can be described by considering only a selected subset of all possible T = 0, 1 pairs.