F-spin symmetric limits of the neutron-proton interacting boson model

The F-spin symmetric limits U(5), SU(3), and O(6) of the neutron-proton interacting boson model are studied. The conditions for and consequences of F-spin symmetry are investigated. In each of the three limits closed expressions for the following properties are given: the excitation energies; the M1, E2, and M3 excitation strengths from the ground state to all 1+, 2+, and 3+ states; the M1 and E2 decay of the nonsymmetric 1+ and 2+ states; and the dipole and quadrupole moments of maximal F-spin states and of the nonsymmetric 1+ and 2+ states. The predictions for these properties are compared with the experimental data