Yu Shao-Ying

Calculation of triaxial superdeformation in Hf-174

A two-dimensional Total Routhian Surface (TRS) calculation with the fixed hexadecapole deformation ε4 = 0.03 was carried out for several configurations of 174Hf. Results indicate that the shell corrections have an important contribution to the formation of triaxial superdeformation in 174Hf and some possible configuration assignments are made to the 4 TSD bands experimentally found in 174Hf.

Identical Bands and Alignment in193,194Tl

The microscopic mechanism of the identical bands in odd–odd nucleus 194Tl and its neighbour odd-A nucleus 193Tl are investigated using the particle-number conserving method with monopole and quadrupole pairing interaction. It is found that the blocking effect 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 alignment of 194Tl bands with respect to the 193Tl(1) band used as a reference is also discussed.

A tentative method for assigning the configuration of a triaxial nuclei in TRS

A tentative method based on the principle of minimum energy is put forward for assigning the reasonable configuration of a triaxial nucleus in TRS. This method is proved by the TSD of 167Lu nucleus that has been calculated previously by TRS.

Formation Mechanism of Triaxial Superdeformed Nucleus 160Yb

By using Total Routhian Surface (TRS) method the deformation of the nucleus 160Yb is studied. The result shows that the triaxial superdeformed state exists with deformation parameters 2 = 0.38 and γ = 21°, where proton shell correction energy plays a key role, and the sum of two quasi-proton particle energies gives an additional driving effect. The rotational energy also has an additional role in the formation of triaxial superdeformed.

Possible existence of triaxial superdeformation in 172,174,176W

Two-dimensional total routhian surface (TRS) calculations are carried out to determine the triaxial superdeformation (TSD) of the even-even nucleus W, and the result indicates that TSD state exists with deformation parameters 2 = 0.42 and ? = 34.7?. In the same way, the total routhian surfaces for the nuclei W are also calculated. It shows that the neutron shell correction energy plays a key role in the formation of TSD nuclei 172,174,176W, while the high j intruder orbitals and rotational energy are also crucial in the formation mechanism.

Total routhian surface calculations on Hf isotopes

The two-dimensional total routhian surface calculations have been carried out to study the triaxial superdeformed structure of a neutron-rich nucleus Hf-173 firstly. In particular the effects of the rotational frequency omega and pairing-energy gap parameter Delta are discussed in detail in the course of shaping its triaxial superdeformation; additionally the neutron-shell correction energy is analyzed with emphasis in the confirmed triaxial superdeformed nucleus Hf-173. Finally, more systematical results have been investigated for some confirmed superdeformed nuclei experimentally and a few predicted triaxial superdeformed nuclei theoretically with quadropole deformation epsilon(2) approximate to 0.4 and triaxial deformation gamma approximate to 20 degrees or 30 degrees in the Z = 72 region.

Study of Triaxial Superdeformation in 162Lu

The triaxially superdeformed states in 162Lu are investigated using the three-dimensional total routhian surface calculation, and the deformation parameters and the likely configuration are given. The shell and pairing correction energies are considered respectively, and the formation mechanism of triaxial superdeformation is investigated.

Triaxial superdeformed band and its formation mechanism in odd-odd nucleus Lu-168

Three-dimensional total Routhian surface calculations are carried out to determine the triaxial superdeformation of odd-odd nucleus Lu-168. One of the new four rotational bands observed in the experiment is identified as a triaxial superdeformed band, in which the neutron shell correction energy plays a key role and the deformation-driving effect of high j intruder orbital plays an additional role in the formation of triaxial superdeformation shape. Its deformation parameters (epsilon(2), epsilon(4), gamma) are derived from the analysis, which can reproduce the experimental assignment.

Blocking Effect and Moments of Inertia of K = 1/2 Rotational Band in 171Yb

The K = 1/2 rotational band in Yb-171 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 Yb-171 [521]1/2 (signature alpha = +/-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 omega 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.