Multiple band structures in ${}^{179}\mathrm{Au}$ are established from $\gamma$-ray spectroscopic measurements with Gammasphere at the Argonne Fragment Mass Analyzer. The yrast band, based on the $13∕2^{+}$ proton, confirms the predicted drop in excitation energy of the prolate deformed band head as compared to the heavier isotopes. The implications for the prolate energy minimum in odd-mass Au nuclei beyond the neutron $i_{13∕2}$ midshell $(N<102)$ are discussed.

• Received 2 February 2004

DOI:https://doi.org/10.1103/PhysRevC.69.064315