M1 PROPERTIES OF TUNGSTEN ISOTOPES IN THE INTERACTING BOSON MODEL .2.

The M1 properties of even W-182-186 isotopes are investigated in the i nteracting boson model-2 (IBM-2). The E2/M1 mixing ratios, g factors, and summed M1 strength are calculated. A least-squares fit of the exci tation energies is used to fix the IBM-I projected Hamiltonian paramet ers, while the F-spin-breaking terms are adjusted to reproduce the M1 properties of low-lying states. The influence of F-spin mixing on the summed M1 strength is studied using the coherent state technique in pe rturbation theory. When the standard boson g factors are used, the M1 properties of the low-lying states are described satisfactorily, but t he summed M1 strengths are found to be larger than present experimenta l values. Possible g factor adjustment, which reconciles the calculate d and experimental M1 strength, is discussed.