Structure of high spin states in the A = 80 region

Many spectroscopic phenomena can be observed in the neutron deficient mass 80 region. Shape coexistence effects can be found in the Se isotopes resulting in moderately deformed nuclei (1Q: 1 ∼ 1.7 b) (see contribution to these proceedings by J Eberth) while only four protons away strong prolate deformations (1Q: 1 ∼ 3.3 b) are found in the Sr isotopes. Such a strong variation in structure is uniquely characteristic of this mass region, due to the low single particle density which results in large shell gaps for strong prolate and oblate deformations [Li86]. The active high-j single particle orbital for both protons and neutrons is the g9/2 π = + orbital. Since the frequencies where quasiparticle alignment takes place are similar for both kinds of nucleons, the character of the aligning particles is usually determined through systematics and blocking arguments. More recently [Ku88], g factor measurements have been used to directly determine which particles are aligning. In this paper, the authors present experimental results which highlight the varied structural and alignment characteristics found in the Br-Zr isotopes