DECAY-OUT OF THE HIGHLY-DEFORMED BANDS IN THE A=130-140 MASS REGION

摘要

Transitions linking the highly deformed band to low deformation states have been established in ~(137)Nd, ~(137)Sm, ~(139)Sm and ~(139)Gd with experiments performed at GASP. Whereas in ~(137)Nd the linking transitions account for 25% of the band intensity, in the other three nuclei almost 100% of it is found. The data prove that the HD bands are built on the vi_(13/2)[660]1/2~+ intruder orbital. In all cases, the sudden termination of the HD band is explained through the disappearance of the second minimum in the potential energy surface. A wide systematic of excitation energies and spin is now available for detailed comparison with calculations.