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 ～ ...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 γ-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.展开更多
Experimentally observed ground state band based on the 1/2-[521] Nilsson state and the first exited band based on the 7/2-[514] Nilsson state of the odd-Z nucleus 255Lr are studied by the cranked shell model （CSM） w...Experimentally observed ground state band based on the 1/2-[521] Nilsson state and the first exited band based on the 7/2-[514] Nilsson state of the odd-Z nucleus 255Lr are studied by the cranked shell model （CSM） with the paring correlations treated by the particle-number-conserving （PNC） method. This is the first time the detailed theoretical investigations are performed on these rotational bands. Both experimental kinematic and dynamic moments of inertia （f^（1） and ,f^（2） versus rotational frequency are reproduced quite well by the PNC-CSM calculations. By comparing the theoretical kinematic moment of inertia f（1） with the experimental ones extracted from different spin assignments, the spin 17/2- →13/2- is assigned to the lowest-lying 196.6（5） keV transition of the 1/2- [521 ] band, and 15/2→11/2- to the 189（1） keV transition of the 7/2- [514] band, respectively. The proton N = 7 major shell is included in the calculations. The intruder of the high-j low→lj15/2 （1/2-[770]） orbital at the high spin leads to band-crossings at hω = 0.20 （hω~=0.25） MeV for the 7/2-[514]ω= -1/2 （ω= ＋1/2） band, and at hω=0.175 MeV for the 1/2- [521 ] ω= - 1/2 band, respectively. Further investigations show that the band-crossing frequencies are quadrupole deformation dependent.展开更多
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 rotati...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 Kπ= 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,J（1） in these two-particle bands compared with the ground state band is attributed to the pairing reduction due to the Pauli blocking effect.展开更多
文摘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 γ-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.
基金supported by the National Natural Science Foundation of China(Grant Nos.11275098 and 11275067)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Experimentally observed ground state band based on the 1/2-[521] Nilsson state and the first exited band based on the 7/2-[514] Nilsson state of the odd-Z nucleus 255Lr are studied by the cranked shell model （CSM） with the paring correlations treated by the particle-number-conserving （PNC） method. This is the first time the detailed theoretical investigations are performed on these rotational bands. Both experimental kinematic and dynamic moments of inertia （f^（1） and ,f^（2） versus rotational frequency are reproduced quite well by the PNC-CSM calculations. By comparing the theoretical kinematic moment of inertia f（1） with the experimental ones extracted from different spin assignments, the spin 17/2- →13/2- is assigned to the lowest-lying 196.6（5） keV transition of the 1/2- [521 ] band, and 15/2→11/2- to the 189（1） keV transition of the 7/2- [514] band, respectively. The proton N = 7 major shell is included in the calculations. The intruder of the high-j low→lj15/2 （1/2-[770]） orbital at the high spin leads to band-crossings at hω = 0.20 （hω~=0.25） MeV for the 7/2-[514]ω= -1/2 （ω= ＋1/2） band, and at hω=0.175 MeV for the 1/2- [521 ] ω= - 1/2 band, respectively. Further investigations show that the band-crossing frequencies are quadrupole deformation dependent.
基金Supported by the National Natural Science Foundation of China(11775112,11535004,11875027,11761161001)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘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 Kπ= 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,J（1） in these two-particle bands compared with the ground state band is attributed to the pairing reduction due to the Pauli blocking effect.
