Very extended shpaes in the A ∼ 150 mass region

There was a report of a rotational band in 152Dy or 153Dy that is characterized by a dynamic moment of inertia of 130h2 MeV-1. For purposes of orientation, it should be noted that the well known superdeformed bands in this region are characterized by moments of inertia of ∼90. Some calculations were carried out in two- and three-dimensional shape spaces, in order to understand this experimental observation. These calculations show either very shallow minima and/or minima that do not become yrast below I = 90 at the very large deformations that would seem to be required to explain such a large moment of inertia. We extended our four-dimensional deformation space Strutinsky calculations to a study of this mass region, with the hope of gaining some insight into the nature of this band. We are also analyzing the other nuclides of this mass region with the hope of finding other instances of such very extended shapes. This analysis is almost complete