Shape coexistence in Au187

The level structure of odd-proton Au187 was studied using the Yb172(19F,4n) reaction. Gamma-gamma coincidence, angular distributions and γ-γ-time measurements were used to establish the energies, spins, parities, and lifetimes for the states in the decay scheme of Au187. Both prolate and oblate structures have been established. The prolate bands are built on the πh9/2 (α=±(1/2) and the πi13/2 (α=(1/2) particle states. An oblate, strongly coupled band built on a 90±10 ns isomeric state is reported for the first time. A second oblate structure built on the h11/2 proton-hole state was established to much higher spin than before. The backbend present in the πi13/2 band has been interpreted as the alignment of a pair of h9/2 protons.