A new generalization of vector-coherent state theory for the SO(5)U(2) proton-neutron quasispin group

Abstract

The introduction of a set of intrinsic coordinates to give an explicit construction of the intrinsic states of vector-coherent state theory has greatly simplified earlier attempts to generalize this theory to include operators lying outside the group algebra. Very explicit vector-coherent state construction of such operators can now be given in terms of vector-coupled combinations of intrinsic and collective operators. When organized into tensors which induce specific shifts in irreducible representations these lead to the reduced Wigner coefficients needed in practical calculations. The SO(5)U(2) proton-neutron quasispin algebra is used as an example to give further simplifications of earlier results. All Wigner coefficients needed to give the n,T-dependence of matrix elements in the seniority scheme can now be given through a few terms expressed solely through angular momentum recoupling coefficients and the K-matrix elements of vector-coherent state theory.