Validity of the broken-pair approximation for N=50, even-A nuclei

The validity of the broken-pair approximation as an approximation to the seniority shell model is investigated. The results of the broken-pair approximation and the seniority shell model, obtained by employing identical input information (single-particle levels and their energies, effective two-body matrix elements, Sr88 inert core) for N=50, even-A nuclei are compared. A close agreement obtained between the calculated broken-pair approximation and the seniority shell model energies for Zr90, Mo92, Ru94, and Pd96 nuclei and large (95-100%) overlaps between the broken-pair approximation and the senority shell model wave functions for Mo92, demonstrates the validity of the broken-pair approximation in this region and in general its usefulness as a good approximation to the seniority shell model. NUCLEAR STRUCTURE Shell model, seniority shell model, broken-pair approximation, quasiparticle Tamm-Dancoff (QTD), projected QTD; Zr90, Mo92, Ru94, Pd96.