A systematic study of two-quasiparticle bands of the proton-rich odd-odd nuclei in the mass $A\sim 70–80$ region is performed using the projected shell model approach. The study includes Br, Rb, and Y isotopes with $N=Z+2\mathrm{}$ and $Z+4.\mathrm{}$ We describe the energy spectra and electromagnetic transition strengths in terms of the configuration mixing of the angular-momentum projected multi-quasiparticle states. Signature splitting and signature inversion in the rotational bands are discussed and are shown to be well described. A preliminary study of the odd-odd $N=Z$ nucleus ${}^{74}\mathrm{Rb},$ using the concept of spontaneous symmetry breaking is also presented.

• Received 3 September 2002

DOI:https://doi.org/10.1103/PhysRevC.67.014321