Mixed symmetry states and electromagnetic transition in the N=Z nucleus ^28Si

The interacting boson model with isospin （IBM-3） has been used to study mixed symmetry states and electromagnetic transitions at low-lying states for a ^28Si nucleus. The theoretical calculations show that the 24^＋ state is the lowest mixed symmetry state in ^28Si and the 43＋ state is also a mixed symmetry state.     

Electromagnetic transition properties and isospin excitation in the cross-conjugate nuclei 44Ti and 52Fe

The interacting boson model with isospin (IBM-3) is applied to study the band structure and electromagnetic transition properties of the low-lying states in the cross-conjugate nuclei ⁴⁴Ti and ⁵²Fe. The isospin excitation states with T=0, 1 and 2 are identified and compared with available data. The E2 and M1 matrix elements for the low-lying states have been investigated. According to this study, the 2₃⁺ state is the lowest mixed symmetry state in the cross-conjugate nuclei ⁴⁴Ti and ⁵²Fe. The excitation energy of the second 0₂⁺ and 2₂⁺ states with T=0 in the nucleus ⁵²Fe are identified. The agreement between the model calculations and data is reasonably good.     

Low-lying spectra and E2 transition rates in 160-170Er isotopes in the interaction boson model

Spectra and E2 transition rates for the ^160-170Er isotopes are studied in the framework of the interaction boson model. A schematic Hamiltonian able to describe their spectra and B(E2) transition is used. It is found that the ^160-170Er isotopes are in the transition from the vibrational limit to rotational limit.     

Isospin structure in 68Ge

The interacting boson model-3(IBM-3) has been used to study the low-energy level structure and electromagnetic transitions of 68Ge nucleus. The main components of the wave function for some states are also analyzed respectively. The theoretical calculations are in agreement with experimental data, and the 68Ge is in transition from U(5) to SU(3).     

Isospin and mixed symmetry structure in ~(26)Mg

The isospin excitation states and electromagnetic transitions of the ²⁶Mg nucleus are studied with the isospin-dependent interacting boson model (IBM-3). The mixed symmetry states at low spin and the main components of the wave function for some states are also analyzed. The results show good agreement with the available experimental data. From the IBM-3 Hamiltonian expressed in Casimir operator form, the ²⁶Mg is also proved to be a transition nuclei from U(5) to SU(3).     

164—182Hf核的低能谱和电磁跃迁的相互作用玻色子模型

采用相互作用玻色子模型研究了^164—182Hf偶偶核的低能谱和电磁跃迁, 应用一个U(5)→SU(3)简化哈密顿量很好的描述它们的低能谱和电磁跃迁过渡. 结果表明^164—182Hf同位素核基本上属于U(5)→SU(3)的过渡核.     

Critical behaviour in nuclear structure from spherical to axially symmetric deformed shape in IBM

To compare with the predictions of the transitional dynamical symmetry X（5） proposed by Iachello （2001 Phys. Rev. Lett. 87 052502）, the critical behaviours of U（5） SU（3） are studied in the space of two control parameters in the interacting boson model （IBM）. A simple-shaped phased diagram has been presented. It is found that X（5） predictions cannot be exactly reproduced by our calculations and that the best agreement is close to the calculations with boson numbers N = 11 and 12. By comparing with experimental data on X（5）-like nuclei, we find that X（5） predictions and IBM calculations can reproduce the energy ratios and E2 transition ones.     

140-162Gd核的低能谱和电磁跃迁的相互作用玻色子模型

采用相互作用玻色子模型研究了140-162Gd偶偶核的低能谱和电磁跃迁,应用一个U(5)→SU(3)的简化哈密顿量很好地描述它们的低能谱和电磁跃迁过渡.结果表明140-162Gd同位素核基本上属于U(5)→SU(3)的过渡核.     

Mixed symmetry states and electromagnetic transition in the N=Z nucleus ~(28)Si

The interacting boson model with isospin (IBM-3) has been used to study mixed symmetry states and electromagnetic transitions at low-lying states for a ²⁸Si nucleus. The theoretical calculations show that the 2₄⁺ state is the lowest mixed symmetry state in ²⁸Si and the 4₃⁺ state is also a mixed symmetry state.     

Isospin and mixed symmetry structure in 24Mg

The interacting boson model with isospin (IBM-3) has been used to study the isospin excitation states and electromagnetic transitions for ²⁴Mg nucleus. The mixed symmetry states at low spin are also analyzed. The theoretical calculations are in agreement with experimental data. The present calculations indicate that the 3₁⁺ state is the lowest mixed symmetry state.