V.K.B. KOTA

Ahmedabad 380 009, India ABSTRACT. The SU(3) dynamical symmetry ofinteracting basan model (IBM), which is appropri-ate for heavy deforrned nuclei, appears in various extended versions of the rnodel; for example in the proton-neutron IBM (pn-IBM) that distinguishes proton (7r) and neutron (v) bosons, the sdgIBM that includes hexadeeupole g (i = 4) bosons, the interacting boson-n-fermion model (IBF"M) where n-fermions or quasi particles are eoupled to IBM eore etc. Results of sorne applications of these models where the SU(3) limit appears, are given and they are: (i) identification of a basis and hamiltonian within the [U'd(6)::J SU'd(3)] 0 U9(9) limit that generate for even-even nuclei the tJ.L = 4 staggering (g bosons, no 7r-V, n = O); (ii) asymptotic limit expressions for B(E2)'s and B(MI)'s in the Bose-Fermi SUBF (3) limit and analysis of 1S50Sand l75Re data (n = 1, no g or 7r-V bosons); (iii) developing the SUBF(3) 0 UF(2j + 1) limit for heavy deformed odd-odd nuclei (n = 2, no g or 7r-V bosons); (iv) MI distributions in odd mass nuclei in the SU~:'(3) and SU~J(3) 0 U9(9) limits (7r-V and g bosons, n = 1). RESUMEN.La simetría dinámica de SU(3) del modelo de bosones interactuantes (MBI), apropiado para núcleos pesados deformes, aparece en varias extensiones del modelo; por ejemplo, en el MB