M1 transitions in the SU(3) shell model

M1 transitions in isotopes of Gd and Dy are calculated within the framework of the pseudo-SU(3) model. Basis states are built as linear combinations of direct product SU(3) proton and neutron configurations coupled to total pseudo-spin zero. The system Hamiltonian includes spherical Nilsson single-particle energies, the quadrupole-quadrupole and pairing interactions, as well as four SU(3) symmetry preserving rotor terms. The calculated results compare favorably with the experimental data. The M1 transitions give rise to a unique interpretation of the outer multiplicity that enters in a reduction of the direct product of SU(3) irreducible representations. For comparison, some results for light sd-shell and transitional fp-shell nuclei (e.g. 20Ne and 44Ti) are also presented