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1.
The K=1/2 rotational band in
171Yb is investigated
using the particle number conserving (PNC) method for treating the cranked
shell model with monopole and quadrupole pairing interactions. The
experimental moments of inertia of
171Yb [521]1/2 (signature α =±1/2) are reproduced well by the PNC calculation, in which no free
parameter is involved. The difference in the contribution to the moment of
inertia between protons and neutrons is mainly due to the blocking effect of
neutron normal orbitals. The ω variation of the occupation
probability of each cranked orbital and the contribution to the moment of
inertia from each major shell and from each cranked orbital are
investigated. 相似文献
2.
超变形核中四极对力形式的探讨 总被引:1,自引:0,他引:1
用粒子数守恒方法分析了对力对于超变形(SD)带的转动惯量随角动量(角频率)变化的规律.计算中如包含了单极对力和Y20四极对力,晕SD带194Hg(1)和192Hg(1)的转动惯量在观测的全部角动量范围中的变化规律,都可得到极好的重现,特别是ω≥0.40MeV时,194Hg(1)的J(2)下弯和192Hg(1)J(2)的变平.而考虑Y2±1和Y2±2四极对力的计算结果,都与实验不符.粒子数守恒计算中极清楚地展现了J(2)随ω变化的微观机制(可分别给出各大壳、各推转Nilsson能级上的粒子填布几率和对J(2)的贡献).J(2)随ω变化是粒子壳效应(变形场中单粒子运动)、对关联、Pauli堵塞效应以及Chriolis(反配对)作用相互竞争的结果. 相似文献
3.
The T = 2 excitations in even-even N = Z nuclei are calculated within the isospin cranked mean-field approach. The response of pairing correlations to rotation in isospace is investigated. Whereas the isovector pairing rather modestly modifies the single-particle moment of inertia in isospace, the isoscalar pairing strongly reduces its value. This reduction of the isomoments of inertia with respect to its rigid body value is a strong indicator of collective isoscalar pairing correlations. These results are further generalized yielding beautiful analogies between the role of isovector pairing for the case of spatial rotations and the role of isoscalar pairing for the case of isorotations. 相似文献
4.
The multi-particle states and rotational properties of the two-particle bands in 254No are investigated by the cranked shell model with pairing correlations treated by the particle number conserving method.The rotational bands on top of the two-particle K^π=3^+,8^− and 10^+ states and the pairing reduction are studied theoretically in 254No for the first time.The experimental excitation energies and moments of inertia of the multi-particle states are reproduced well by the calculations.Better agreement with the data is achieved by including the high-order deformation ε6,which leads to enlarged Z=100 and N=152 deformed shell gaps.An increase of J1 in these two-particle bands compared with the ground state band is attributed to the pairing reduction due to the Pauli blocking effect. 相似文献
5.
V. G. Neudatchin L. L. Sviridova N. P. Yudin S. N. Yudin 《The European Physical Journal A - Hadrons and Nuclei》2005,24(2):217-222
The microscopic mechanism of the identical bands in odd-odd nucleus 194Tl and its neighbor odd-A nuclei 193,195Tl is investigated using the particle-number-conserving (PNC) method for treating the cranked shell model with monopole and quadrupole pairing interactions. It is found that the blocking effect of the high-j intruder orbital plays an important role in the variation of moments of inertia (J(1) and J(2)) with rotational frequency for the superdeformed bands and identical bands. The variation of the occupation probability of each cranked orbital and the contributions to moment of inertia from each cranked orbital are presented. 相似文献
6.
Six superdeformed bands of odd-odd nucleus 194Tl in A~190 mass region are studied using the particle-number conserving method for treating the cranked shell model with pairing interactions. Calculated results agree with experiments very well. Based on our calculation the configurations of the six superdeformed bands are assigned and the influence of blocking effects of proton and neutron on moments of inertia is investigated in detail. The variation of moments of inertia with rotational frequency is mainly attributed to the intruder shells (neutron N=7 and proton N=6), whereas the contributions to moment of inertia from other shells remain almost unchanged with rotational frequency. 相似文献
7.
Seven experimentally observed bands of 155Tb are analyzed in detail, using the particle-number-conserving method for treating the cranked shell model with monopole and quadrupole pairing interactions. We satisfactorily reproduce the experimental alignments and especially focus on the microscopic mechanism of the second back-bending and the influence of pair interaction on ultrahigh spins. Our calculated results show that the πi13/2 orbitals are too high to give a contribution to the moment of inertia below hω≈0.7 MeV. Instead, the crossing between the π[541]l/2 and other proton orbitals is responsible for the second back-bending. We assign a possible configuration to the decoupled band found in 155Tb and predict eleven bands which are experimentally unobserved. 相似文献
8.
The variations of moments of inertia of superdeformed (SD) bands 194Hg(1)and 192Hg(1) with angular momentum (rotational frequency) are investigated using the particlenumber conserving (PNC) method for treating the cranked shell model. Calculations show that if both the monopole and Y20 quadrupole pairing forces are taken into account, the observed co variation of the moments of inertia of 194Hg(1) and 192Hg(1) can be reproduced very well both in the low-and high- ranges, in particular the J(2) downturn of 194Hg(1) and the flattening in J(2) of 192Hg(1) at>0.40MeV. On the contrast, the calculated J(2)'s with the Y2±1 or Y2±2 quadrupole pairing forces are in disagreement with the experiments. The microscopic mechanism of the co variation of J(2) is clearly exhibited in the PNC calculation (the contributions to J(2) from various major Shells and individual cranked Nilsson orbitals, the occupancy of each cranked Nilsson Orbital etc). The variation of moment of inertia is the result of the competition among the shell effect (single particle motion in a deformed potential), pairing correlation, Pauli blocking effect and Coriolis (anti-pairing) interaction. 相似文献
9.
通过系统研究A~190区超形变核中转动带的转动惯量、角动量顺排、旋称分裂随转动频率的变化规律, 结合我们用处理对力的粒子数守恒方法的计算结果, 对A~190区所有转动带的组态结构给出了一个整体的描述. 绝大多数超形变带都建立在强耦合轨道上, 例如中子[512]5/2, [624]9/2. 少数超形变带则建立在高j闯入轨道上, 即中子[761]3/2, [752]5/2. 根据我们提出的组态结构所进行的理论计算结果表明, A~190区所有转动带的一般行为、反常变化和带交叉都得到了满意的解释. 相似文献
10.
The microscopic mechanism of nine experimentally observed bands in
178W is investigated using the particle-number conserving
method of the cranked shell model with monopole and quadrupole paring interactions. The experimental results, including the moments of inertia and angular momentum alignments of nine bands in 178W, are reproduced well by the particle-number conserving calculations, in which no free parameter is involved. Calculations
demonstrate that occurrence of sharp backbending comes mainly from
the contribution of high-j intruder orbitals νi13/2 or πh11/2 and their interference effect with orbitals near the Fermi surface. The ω variation of the occupation probability of
each cranked orbital and the contribution to moment of inertia from
each cranked orbital are analyzed. 相似文献
11.
采用基于推转壳模型的粒子数守恒方法对105Cd 和106Cd 中的反磁转动带进行了研究,在计算当中,粒子数严格守恒,并且堵塞效应也是严格考虑的。计算结果很好地再现了实验上观测到的I-Ω 关系、转动惯量以及约化跃迁几率B(E2)。通过检验双剪角,即两个质子空穴角动量的合拢,对反磁转动中的双剪刀机制进行了分析。研究表明剪刀角的合拢非常敏感地依赖于对关联。The antimagnetic rotation bands in 105;106Cd are investigated by the cranked shell model with pairing correlations treated by a particle-number conserving method, in which the blocking effects are taken into account exactly. The experimental moments of inertia, I-Ω relation and the reduced B(E2) transition probabilities are well reproduced. The two-shears-like mechanism for the antimagnetic rotation is investigated by examining the shears angle, i.e., the closing of the two proton hole angular momenta. The sensitive dependence of the shears angle on the nuclear pairing correlations is revealed. 相似文献
12.
The experimentally observed ten rotational bands in 179Re are analyzed with the particle-number conserving method for treating the cranked shell model with pairing interaction, in which the blocking effects are taken into account exactly. The experimental moments of inertia of these bands are reproduced quite well by our calculations with no free parameter and the deformation driving effects are discussed. The bandhead energies and the variation in the occupation probability of each cranked orbital are also analyzed. 相似文献
13.
The shell correction method for rotating nuclei was generalized to include pairing correlations. This extends the applicability of the cranked Strutinsky-type calculations to the low-spin region. As an illustrative example the yrast-line of24Mg is studied. 相似文献
14.
The iron-based superconductivity (IBSC) is a great challenge in correlated system. Angle-resolved photoemission spectroscopy (ARPES) provides electronic structure of the IBSCs, the pairing strength, and the order parameter symmetry. Here, we briefly review the recent progress in IBSCs and focus on the results from ARPES. The ARPES study shows the electronic structure of "122", "111", "11", and "122 " families of IBSCs. It has been agreed that the IBSCs are unconventional superconductors in strong coupling region. The order parameter symmetry basically follows s ± form with considerable out-of-plane contribution. 相似文献
15.
The microscopic mechanism of four experimentally observed bands in 172Tm is investigated using the particle-number conserving method of the cranked shell model with monopole and quadrupole paring interactions.The experimental results,including the moments of inertia and angular momentum alignments of four bands in 172Tm are reproduced well by the particle-number conserving calculations.The ω variation of the occupation probability of each cranked orbital and the contribution to moment of inertia from each c... 相似文献
16.
17.
The particle-number conserving (PNC) method for treating the cranked shell model with monopole and quadrupole pairing correlations is used to study the superdeformed (SD) bands observed in odd–odd nuclei in the A190 mass region. Spins are assigned to the levels in these bands. The microscopic mechanism of the ω evolution of the dynamic moment of inertia J(2) for these SD bands are analyzed. In particular, the major roles of the j15/2 neutron and i13/2 proton orbitals played in the SD bands are investigated in detail by contributions to J(2) from each cranked orbital and interference terms between two cranked orbitals. Additivity in the A190 mass region is investigated. The experimental evidence for additivity of alignments in 192Tl can be reproduced by our calculations. 相似文献
18.
The experimental one-, three-, and five-quasiparticle bands in 177Lu are analyzed by the particle-number conserving (PNC) method for treating the cranked shell model with pairing interaction, in which the blocking effects are taken into account exactly. The experimental moments of inertia are reproduced very well by PNC calculations with us free parameter. 相似文献
20.
The experimental one-, three-, and five-quasiparticle bands in ~(177)Lu are analyzed by the particle-number conserving (PNC) method for treating the cranked shell model with pairing interaction, in which the blocking effects are taken into account exactly. The experimental moments of inertia are reproduced very well by PNC calculations with us free parameter. 相似文献