PARITY INVERSION IN THE N=7 ISOTONES AND THE PAIRING BLOCKING EFFECT

The parity inversion anomaly in the spectra of N=7 isotones is discuss ed based on contemporary shell-model wave functions. It is shown that the proton-neutron monopole interaction in the mean field has a large effect on the energy gap between the 1/2- and 1/2+ states in Be-11, bu t not enough to explain the inverted spectrum. We point out that the e ffects of quadrupole core excitation and pairing blocking are equally important to make the parity inversion in Be-11. It is predicted that He-9 has also a parity inversion in the ground state due to the pairin g blocking.