Superfluid-to-normal phase transition in superdeformed bands

A semiclassically exact solution for the second inertial parameter Β is found for the superfluid and normal phases. An interpolation between these limiting values shows that Β changes sign in the transition region at the spin Ic that is critical for the rotational spectrum. A superfluid-to-normal transition reveals itself in a specific variation of Β versus the spin I. Experimental data show the existence of a transition for superdeformed bands in the A∼80, 130, and 150 mass regions and for some bands characterized by a normal deformation. A transition to the normal phase explains the extreme regularity of superdeformed bands