Study of platinum isotopes: A comparison of the fermion dynamical symmetry model and the Interacting Boson Model

The systematics of the even platinum isotopes are described within the framework of the Fermion Dynamical Symmetry Model. By using a pairing-plus-quadrupole type interactions, we show that the transitional behavior of these isotopes can be effectively accounted for. Good agreement is obtained between theory and data for energy levels, B ( E,) values, electric quadrupole moments, gyromagnetic factors, and the isomer shifts and isotope shifts for Pt190-196. The Calculations are also compared with various results obtained from the Interacting Boson Model. Consequently, our numerical calculation show that a very accurate effective SO(6) dynamical sysmmetry exists around Pt-196, even though the protonneutron coupled system ( SOx (8) x SPv (6)) does not formally contain such a dynamical symmetry in the fermion dynamical symmetry model. Implications of this effective dynamical symmetry are discussed.