Wigner coefficients for the proton-neutron quasispin group

SO(5) contains U(2) reduced Wigner coefficients, needed to extract the n, T-dependence of nuclear matrix elements in the seniority scheme, are evaluated by vector coherent state techniques by casting operators other than the group generators into their Bargmann z-space realizations. Results are given, in terms of simple angular momentum recoupling coefficients and the K-matrix elements of vector coherent state theory, for SO(5) couplings involving the 4-, 5-, and 10-dimensional representations. Both a simplification of earlier results and a generalization to states of arbitrarily high seniority has been achieved. (orig.)