Mixed Symmetry Isomeric States in Nuclei

Mixed symmetry states are studied in the framework of the neutron-proton interacting boson model. It is found that some of the mixed symmetry states with moderate high spins change very fast with respect to the Majorana interaction. Under certain conditions, they become the yrast state or yrare state. These states are difficult to decay and become very stable. This study suggests that a possible new mode of isomers may exist due to the special nature in their proton and neutron degrees of freedom.

Mixed symmetry states and isospin excitation in the N =Z nucleus ^(28)Si

The interacting boson model with isospin (IBM-3) has been used to study the isospin excitation states and mixed symmetry states at low spin for 28Si. The theoretical calculations are in agreement with experimental data. The theoretical results show that the 81+ energy is 14.73 MeV.

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 Symmetry Structure in ^(36)Ar

The interacting boson model-3(IBM-3) has been used to study the isospin excitation states and electromag-netic transitions for ^(36)Ar nucleus.The mixed symmetry states and superdeformed band at low spin are also analyzed.The theoretical calculations are in agreement with experimental data,and the ^(36)Ar is superdeformed rotational nucleusclose to the SU(3) limit.The present calcula,tions indicate that the 2_4^+ state is the lowest mixed symmetry state and thelowest isospin T=1 excitation state and at about 6.2 MeV,and the bandhead of superdeformed band is 0_2^+ state.

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）.

Isospin and mixed symmetry structure in ^(24)Mg

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 3^＋ state is the lowest mixed symmetry state.

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

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 S2Fe. 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 2＋3 state is the lowest mixed symmetry state in the cross-conjugate nuclei 44Ti and 52Fe. The excitation energy of the second 0＋2 and 2＋2 states with T=0 in the nucleus 52Fe are identified. The agreement between the model calculations and data is reasonably good.