The spdf IBA analytical description of odd parity states in the actinide region

An extension of the IBA 1/Λ asymptotic scheme to the description of odd parity states via the introduction of odd l bosons in the condensate is presented. The new features that are thereby introduced into the system are highlighted and the advantages of using such an approach are discussed. A standard minimization routine is used to determine the structure coefficients for the wavefunctions of the system and to obtain a fit to the spectra and the electromagnetic transition rates of 11 nuclei in the actinide region with a rather small number of variable parameters, namely the single-particle energies and the multipole interaction strengths. Reasonable results are obtained and are compared to the results of exact numerical calculations and earlier 1/N calculations.