Shape Coexistence At The Outer Edges Of Stability

With the coupling of large gamma-ray arrays to recoil mass spectrometers, in-beam gamma-ray studies can be performed on nuclei lying at the very edges of stability. We have recently performed in-beam experiments using Gammasphere coupled to the FMA to measure excited states in proton unbound Au isotopes and neighboring Hg isotopes. These studies have allowed us to characterize the evolution of nuclear shapes as one approaches the proton drip line. In two of the isotopes studied, namely, Au-175 and Hg-179, structures built on three distinct shapes at low excitation energy have been observed.