INTERACTING VECTOR BOSON MODEL AND OTHER VERSIONS OF INTERACTING BOSON APPROXIMATIONS

The general features of the mapping of boson pairs on new bosons are i nvestigated. The results obtained for exact boson mapping of the sp(2d , R) algebra on the u(d)-boson algebra are then applied to the special case of algebra sp(12, R) (d = 6) which is the dynamical symmetry alg ebra of the interaction vector boson model (IVBM). The Dyson mapping o f the IVBM on a version of the standard IBM with dynamical symmetry U( 21) is obtained. This version of IBM contains the S(T = 1), D(T = 1) a nd P(T = 0) bosons, where T is the isospin of the bosons. The problem of elimination of spurious states and Hermitization of this boson repr esentation is discussed. The image of the IVBM Hamiltonian in the spac e of the S, D, P-bosons is found.