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 ¹³⁷Nd, ¹³⁷Sm, ¹³⁹Sm and ¹³⁹Gd with experiments performed at GASP. Whereas in ¹³⁷Nd 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 u i_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.