STRUCTURE OF ODD-A 1S0D-SHELL AND 1P0F-SHELL NUCLEI IN THE COLLECTIVEPAIR APPROXIMATION

The structure of states of nuclei with three and five active nucleons in the 1s0d and 1p0f shells is studied in the framework of the collect ive pair approximation. The collective pairs determined by diagonalizi ng the Hamiltonian in the space of two nucleons outside closed shells are considered as building blocks to describe a nucleus with 2k + 1 nu cleons in terms of k pairs coupled to one nucleon. It is shown that th e low-lying, shell-model spectrum can be described quite well by consi dering only a selected subset of all possible collective pairs.