PAIRING EFFECTS IN N=82 ISOTONES

The importance of pairing effects in the N=82 isotones is extensively investigated by studying the string of nuclei with A ranging from 135 to 151. The pairing Hamiltonian is treated by an equations-of-motion method which is strictly number conserving. The coupling strength is determined by an analysis of the properties of the even-mass isotones. The single-particle energies are extracted from the experimental spectra of Cs137 and Eu145 through use of the equations which give the energies of the seniority-one states in a way which is analogous to the inverse gap equation method. A detailed comparison of the calculated results with experimental data in even and odd nuclei provides firm evidence of the prominent role of proton pairing correlations in the 50 <>82 shell. It is found that non-negligible correlations are present in Gd146. © 1990 The American Physical Society.