用I(I+1)展开式分析超形变带

用Bohr－MottelsonI（＋1）展开四参数转动谱公式系统分析了A～190、150区的超形变转动带．结果表明：四参数ABCD公式能够相当好地描述上述两个区的超形变带,若干核第二类转动惯量J(2)的理论计算值与实验提取值符合较好;A～190区超形变带的四参数数值关系并不支持Harris公式及ab公式的理论预期值,但相对而言,ab公式的理论预期值与实验提取值更为接近．     

Description of the Superdeformed Bands of Odd-Odd Nuclei in A ～ 80 Region

Properties of the superdeformed bands of odd-odd nuclei in A～80 mass region are investigated systematically within the supersymmetry scheme including many-body interactions and a perturbation possessing the SO(5) (or SU(5)) symmetry on the rotational symmetry. The obtained γ-ray energies, and the dynamical moments of inertia agree with experimental data. It shows that this approach is quite powerful in describing odd-odd nuclei in A～80 mass region.     

转动对超形变带能谱和M1跃迁的影响

利用三轴粒子－转子模型研究了转动对超形变带能谱和Ｍ１跃过的影响．给出了１９５ＴｉＳＤ带的能谱，Ｓｉｇｎａｔｕｒｅ分离，Ｂ（Ｍ１）值和Ｅ２γ跃迁强度．１９５Ｔ１Ｓｉｇｎａｔｕｒｅ伙伴带之间的Ｍ１跃迁主要通过内转换电子进行．     

Description of Properties of Triaxial Superdeformed Bands in Odd-A Lu Isotopes

Properties of the triaxial superdeformed （TSD） bands of odd-A Lu isotopes are investigated systematically within the supersymmetry scheme including many-body interactions and a perturbation possessing the S0（5） （or SU（5）） symmetry on the rotational symmetry. Quantitatively good results of the γ-ray energies, the dynamical moments of inertia and the spin of the TSD bands in odd-A Lu isotopes are obtained. The calculation shows that the competition between the pairing and anti-pairing effects exists in these TSD bands. Meanwhile, the SU（3） symmetry in TSD bands are broken more seriously than in superdeformed （SD） bands.     

Systematic study of rotational energy formulae for superdeformed bands in La and Ce isotopes

The experimental rotational spectra of superdeformed(SD) bands of ~(130)La, ~(131)Ce(1,2), ~(132)Ce(1,2,3) and133 Ce(1,2,3) in the A～130 mass region are systematically analyzed with the four parameter formula, power index formula, nuclear softness formula, and VMI model. It is observed that out of all the formulae, the four parameter formula suits best for the study of the ~(130)La, ~(131)Ce(1,2), ~(132)Ce(2,3) and ~(133)Ce(1,2,3) SD bands. The four parameter formula works efficiently in determining the band head spin of the ~(130)La, ~(131)Ce(1,2) ~(132)Ce(2,3) and ~(133)Ce(1,2,3) SD bands. Good agreement is seen between the calculated and observed transition energies whenever the accurate spin is assigned. In ~(132)Ce(1), the power index formula is found to work better than the other three formulae. The dynamic moment of inertia is also calculated for all the formulae and its variation with the rotational frequency is investigated.     

Shape Coexistence and Band Termination in Doubly Magic Nucleus 40Ca

Shape coexistence and band structure near yrast line of the Z=N doubly magic nucleus ⁴⁰Ca have been investigated by the configuration-dependent cranked Nilsson-Strutinsky approach. The observed normal deformed and superdeformed bands are explained and the terminating states are confirmed by the calculations. The transition quadrupole moment Q_t of the calculated superdeformed band is in good agreement with the observed one at high spin. There is shape coexistence within the same configuration. Possible normal deformed and superdeformed bands with rotation around the intermediate axis in several interesting configurations of ⁴⁰Ca are discussed. Possible favored superdeformed band terminations in ³⁸Ca and ³⁸Ar are predicted. The experimental results in ³⁸Ar are discussed simply.     

190区超形变带自旋指定的再讨论

利用两类转动惯量随转动频率的变化及其相互关系,对190区Bohr-Mottelson的两参数、三参数和四参数I(I+1)展开公式指定自旋不一致的27条超形变带进行分析,发现其中18条超形变带,它们的带首自旋I₀能够从两类转动惯量随转动频率的变化及其相互关系中可靠地定出.¹⁹²Hg(2)等发生带交叉的超形变带,它们的带首自旋也可通过分析带交叉以前、两类转动惯量随转动频率的变化及其相互关系定出.     

超形变核全同带的研究

简述了超形变原子核全同带的研究进展情况,并以Bohr-Mottelson的I(I+1)展开转动谱公式对部分典型的超形变带进行了分析.发现所谓全同带的确只是两个带的J⁽²⁾比较接近,它们的J⁽¹⁾和J₀并不相等,而且signature对偶带更接近全同.     

190区超形变核态转动惯量的奇偶差分析

用Bohr-Mottelson的I(I+1)展开三参数公式拟合能谱所定出的展开系数,计算190区超形变带的带首转动惯量.计算结果显示:奇A核的带首转动惯量系统大于相邻偶偶核的带首转动惯量,奇奇核的带首转动惯量系统大于相邻奇A核的带首转动惯量,超形变核态带首转动惯量展现出明显的奇偶差现象.     

Pb–Po系列偶偶超变形带转动惯量变化的微观机制

用处理对力的粒子数守恒方法分析了A～190区偶偶核系列晕SD带^192—198Pb(1)和¹⁹⁸Po(1)的转动惯量随角频率变化的规律.计算中同时考虑了单极对力与Y20四极对力.实验结果在计算中得到较好的重视.特别是转动惯量变化的微观机制(包括中子和质子的各大壳以及各单粒子能级的贡献)在计算中得到极为清楚的展现.J⁽²⁾的上升,主要来自高N闯入壳(中子N=7,质子N=6)的贡献,而其它大壳对J⁽²⁾的贡献,基本上不随ω而变化.