Interacting boson approximation model of the tungsten isotopes

Abstract
The interacting boson approximation model of Arima and Iachello and co-workers has been used to make a schematic study of the tungsten isotopes. For each isotope of tungsten we determine the values of the five parameters in the interacting boson approximation Hamiltonian which yield the best fit to the experimental energy spectrum. Based on these values, we can extrapolate to isotopes for which no experimental data exist and can make predictions for future experiments. Using the same values of these parameters for each isotope, we can also obtain the B(E2) transition rates, the ρ(E0) values, the quadrupole moments of the first two excited 2+ states, the two-neutron separation energies, and the isomer and isotope shifts. Where data exist our results, in general, agree very well with experiment, although more experimental information is needed for the isomer and isotope shifts and the quadrupole moments of the excited 2+ states. The long range goal is to understand the origin of the model parameters in terms of a microscopic theory, such as the nuclear shell model.