Switch from short-axis to intermediate-axis rotation in Nd-138
It is pointed out that the triaxial bands in Nd138-140 and in the Lu/Er nuclei can be understood from the same shell structure effects. Two of the bands in Nd-138, interpreted as signature partners, exhibit a crossing at high spins with a signature splitting which is strongly reduced above the crossing. This behavior is unique among the yrast and close-to-yrast configurations, revealing the mechan