High-Spin States of Yrast Bands in Even Pu, Cm, Fm, and No Isotopes

Abstract

The experimental energies of yrast-band states are known up to the spin of $32^{+}$ for some Pu, Cm, Fm, and No isotopes—in particular, for ${}^{248}$Cm. Their unique property is that all states of very long bands in them remain purely collective. The collective character of these bands manifests itself in the fact that the band energies are faithfully reproduced within the phenomenology of the interacting-boson model (IBM1). The uncertainty in the parameters of the model used becomes smaller upon imposing the condition that the deformation-energy depth obtained on the basis of realistic interactions is equal to the deformation-energy depth calculated for the intrinsic state with the values found for the parameters of the IBM1 Hamiltonian.