A new ground-state band level energy formula for transitional nuclei.

A new three parameter formula is proposed for ground-state bands in even-even soft rotors or called transitional nuclei. The new formula blends those of very soft nuclei and well deformed nuclei. Especially, it is found in fact that the formula proposed by P. von Brentano et al. can be derived from our formula if some approximations are adopted and it can be explained why in their work the energy-dependent term beta*E can be dropped. Compared to their formula it can be resulted in that the range of validity of our formula will be much broader than theirs.