Spin-Stabilized Deformation in Transitional Nuclei

Nuclei that lie in the transition region between those that display pure single-particle and pure collective behavior at low spins tend to yield to the fictive forces generated by rotation and undergo structural changes. The role of angular momentum in stabilizing exotic shapes in nuclei has been dramatically demonstrated by observation of superdeformation at high spins in the A ≈130, 150, and 190 regions. Current theoretical predictions also point towards the lighter 80 < A < 100 region as likely terrain for such spin-stabilized deformations. This chapter centers around the high-spin spectroscopy of two transitional nuclei in this mass region, 86Zr and 10lAg, which were studied with the 8π spectrometer at Chalk River and the Gamma-Array at Yale. A status report on the assembly of a unique combination of detection devices for nuclear-structure studies at Yale will also be presented.