Two superdeformed bands have been observed in the nucleus ${}^{145}$Sm in an experiment performed with the Gammasphere multidetector array. One of these bands demonstrates a sudden rise in its dynamic moment of inertia at low frequency which may be related to the interaction between $N=6\mathrm{}$ Nilsson orbitals at the Fermi surface. The other band has a moment of inertia identical to the yrast band of ${}^{149}\mathrm{Gd}$, making it the fourth case in the $A\simeq 150$ mass region of identical bands in nuclei differing by an $\alpha$ particle.

• Received 25 July 1997

DOI:https://doi.org/10.1103/PhysRevC.57.442