Examination of the existence of third, hyperdeformed minima in actinide nuclei

We study the existence of third, hyperdeformed minima in a number of even-even Th, U, and Pu nuclei using the Woods-Saxon microscopic-macroscopic model that very well reproduces first and second minima and fission barriers in actinides. Deep (3-4 MeV) minima found previously by Cwiok et al. are found spurious after sufficiently general shapes are included. Shallow third wells may exist in Th-230,Th-232, with IIIrd barriers <= 200 and 330 keV (respectively). Thus, a problem of qualitative discrepancy between microscopic-macroscopic and self-consistent predictions is resolved. Now, an understanding of experimental results on the apparent third minima in uranium becomes an issue.