铂同位素的研究——费米子动力学对称模型和相互作用玻色子模型的比较

Study of Platinum Isotopes: A Comparison of the Fermion Dynamical Symmetry Model and the Interacting Boson Model

利用费米子动力学对称性模型 (FDSM )系统研究了偶偶核铂的同位素 ,其跃迁可以很好地由对相互作用 +四极相互作用来描述 ,计算了铂 (190— 196Pt)同位素的能级、电四极矩、旋磁比、同质异能移和同位素移动 ,结果表明理论值与实验值符合的很好 .计算结果还与相互作用玻色子模型 (IBM)的结果进行了比较 .计算结果表明即使在FDSM中质子 -中子耦合系统 (SOπ(8)×SPν(6 ) )形式上不包括SO(6 )动力学对称性 ,但 196Pt附近确实存在精确的等效SO(6 )

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 2) values, electric quadrupole moments, gyromagnetic factors, and the isomer shifts and isotope shifts for 190—196Pt. 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 196Pt, even though the proton-neutron coupled system (SO π(8)×SP ν(6)) does not formally contain such a dynamical symmetry in the fermion dynamical symmetry model. Implications of this effective dynamical symmetry are discussed.