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1.
    
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.  相似文献   

2.
邢正  陈星蕖 《中国物理 C》1995,19(4):354-358
利用三轴粒子-转子模型研究了A~190区奇A核超形变全同带,采用标准的BCS方法处理对关联,分析了(191Au,191Hg(b1)),(191Hg(b2),193Hg(b2))和(191Hg(b3),193Hg(b3))三对全同带,指出特定轨道的填充是造成全同带的重要原因.  相似文献   

3.
A new method for spin assignment of superdeformed rotational bands is proposed and it turns out to be more efficient than other methods used before. The application is made to superdeformed bands in A~190 and A~150 mass regions. By analyzing the standard deviation of the fixed gamma-ray energies of an SD band in different methods, the advantage of the present method over the other methods is presented. This method brings then a comprehensive interpretation of the methods used in spin assignment.  相似文献   

4.
Properties of the superdeformed bands of odd-odd nuclei in A ~ 130 mass region are investigatedsystematically within the supersymmetry scheme including many-body interactions and a perturbation possessing theSO(5) (or SU(5)) symmetry on the rotational symmetry. The obtained γ-ray energies, the dynamical moments ofinertia, and energy differences △Eγ - △Erefγ ef agree with experimental data. It shows that this approach is quite powerfulin describing odd-odd nuclei in 130 mass region.  相似文献   

5.
With the supersymmetry scheme including many-body interactions and aperturbation possessing the SO(5)(or SU(5)) symmetry on the rotational symmetry, the superdeformed bands and △I=4 bifurcation of odd-odd nuclei in A ~ 190 mass region are investigated systematically. Good results for the γ-ray energies, the dynamical moments of inertia, and energy differences △Eγ - △Eref γ are obtained. It shows that this approach is quite powerful in describing odd-odd nuclei in the region.  相似文献   

6.
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.  相似文献   

7.
The superdeformed bands in A~190 region were systematically investigated to indicate the existence of ΔI = 4 bifurcation in this region. The behavior of bifurcation was also discussed.  相似文献   

8.
朱志远  J.Konig  P.Ring 《中国物理 C》1996,20(5):448-454
用转动框架中的相对论平均场理论描述超形变核.核流以及相应的矢量介子场空间分量全部被考虑在内.研究结果表明,在质量数相差二的原子核中特定轨道的填充能够产生这样的一些带,其退激发γ能量最多相差几个keV.理论结果在一定的角动量范围可以与实验值比较.  相似文献   

9.
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.  相似文献   

10.
Properties of the triaxiai superdeformed (TSD) bands of Hf isotopes are investigated systematicaily within the supersymmetry scheme including many-body interactions and a perturbation possessing the SO(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 Hf isotopes are obtained. It shows that this approach is quite powerful in describing the properties of the triaxial superdeformation in Hf isotopes.  相似文献   

11.
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.  相似文献   

12.
原子核的振动与转动模型(Ⅲ)A~190区超形变带研究   总被引:1,自引:1,他引:0  
应用推转玻尔-莫特逊哈密顿量导得了超形变带的转动谱公式,应用这一公式研究了在A~190区24个超形变带的跃迁能量和能级自旋,获得了满意的结果.  相似文献   

13.
超形变带Staggering现象的SUq(2)描述   总被引:1,自引:0,他引:1  
利用SUq(2)转动谱公式分析了149Gd(1),148Gd(6)和148Eu(1)超形变带的staggering现象.当选择合适的带首自旋,计算的ΔI=4的分岔和实验提取的结果惊人地吻合,表明q形变或许是产生原子核超形变带staggering现象的原因之一.  相似文献   

14.
Harris公式和ab公式对超形变核转动带的适用性的比较   总被引:1,自引:1,他引:0  
对A≈190区超变形转动带分别用Harris二参数公式和ab公式进行了系统分析.分析结果表明,与正常变形核动带的情况相似,Harris公式与实验有明显的系统偏离,而ab公式则与实验很接近,可以相当精确和方便地描述超变形转动带.  相似文献   

15.
The ΔI = 1 staggering in doubly odd superdeformed nuclei is systematically investigated. Large-amplitude staggerings emerge in a series of the signature partners. The behavior is analyzed and parametrised in the conventional collective model. The spins of signature partner pairs are assigned in ab and modified ab expressions.  相似文献   

16.
将基于组合方法的角动量投影的位能曲面群用于研究铅同位素原子核190,192Pb 的超形变转动带。位能曲面群计算中采用了Gogny D1S 以及Skyrme SkP SLy4 三种相互作用。如用Gogny D1S 相互作用,190Pb 原子核没有明显的超形变转动带,而192Pb 原子核有非常显著的超形变转动带。用W. K. B. 方法计算了192Pb 原子核的超形变带穿透宽度。该穿透宽度很大与用GW模型(Nucl. Phys. A 660 (1999)197)分析实验数据给出的结果相近。在Gogny D1S 相互作用情形下,就角动量投影对位能曲面群的影响作了讨论,发现角动量投影压低了分隔超形变转动带与正常形变转动带之间的位垒。还用Skyrme SkP 和SLy4 相互作用计算了角动量投影的位能曲面群,发现位垒明显高于Gogny D1S 相互作用给出的位垒。在Skyrme 相互作用情形下,192Pb 原子核的超形变带穿透宽度明显小于Gogny 相互作用给出的宽度,但是较SB方法(Phys. Rev. C,60 (1999) 051305) 分析实验数据得到的结果高出几个数量级。于是,对SB 方法提出了质疑,因为它给出了极其微小的传播宽度。The combined method is applied to calculate the angular momentum projected potential energy surfaces (AMPPES) of 190,192Pb. The Supper-deformed(SD) rotational bands of the two nuclei are studied with the AMPPES computed with the Gogny D1S and Skyrme SkP and SLy4 interactions. It is found that there is no pronounced SD band in 190Pb in the case of the Gogny interaction, which is consistent with the experimental observation. A well developed SD band with the Gogny interaction is found in 192Pb. The tunneling width of 192Pb is comparable to that given by the GW approach (Nucl. Phys. A 660 (1999)197) and orders of magnitude larger than that given by the SB approach (Phys. Rev. C 60 (1999) 051305). The influence of the angular momentum projection on the potential energy surfaces is examined in the case of the Gogny interaction for 190,192Pb. It is shown that the angular momentum projection suppresses the barrier separating the SD and ND rotational bands. Higher barriers of the AMPPESs for the two nuclei computed with the Skyrme SkP and SLy4 interactions are obtained compared with those given by the Gogny force. The tunneling width of 192Pb is also big for the Skyrme interactions. We put the SB approach into question which gives only an extremely small spreading width.  相似文献   

17.
用双参数量子群Uqp(u2)理论模型公式对A~190区47条超形变(SD)转动带进行了系统分析.计算得到的Eγ跃迁谱与实验较好地吻合;按转动带自旋指定的3种方案确定194Hg(1),194Pb(1)的带首自旋,结果与实验一致.此外,进一步讨论了核软度参数σ1的物理意义,发现一对旋称对偶带的σ1几乎全等.  相似文献   

18.
应用包含单极对力及四极对力的粒子数守恒方法对A~190区的奇奇核194Tl和奇A核193Tl中的全同带进行了研究.结果发现堵塞效应对全同带的形成及转动惯量随角频率变化的微观机制都起着非常重要的作用.同时文中对194Tl的6条超形变转动带相对于193Tl(1)的角动量顺排i(ω)的量子化也做了研究.  相似文献   

19.
汤杰  刘玉鑫 《中国物理 C》2004,28(10):1055-1064
利用包括多体相互作用和具有SO(5)(或SU(5))对称性的对转动对称微扰的超对称模型方法,对A≈190质量区奇A核的超形变转动带进行系统的研究,无论是E2跃迁γ射线能谱,还是动力学转动惯量都得到与实验结果很好定量符合的结果.这表明,超对称方法不仅可以很好地描述超形变带的整体性质,还可以很好地描述超形变带的ΔI=4分岔和全同带等奇异现象.  相似文献   

20.
李明亮  朱胜江 《中国物理 C》2006,30(11):1078-1082
首先概述了对A≈150区超形变带的自旋指定的进展情况, 到目前为止, 所提出的各种方法对该区超形变带自旋值的指定并不一致. 发现了该区超形变带的实验能谱特性和动力学转动惯量的特性. 并将此特性用于指定A≈150区超形变带的自旋.  相似文献   

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