1. Zr同位素及同核异能态结构的投影壳模型研究
刘艳鑫
中科院近代物理研究所/湖州师范学院
指导教师：孙扬教授 周小红研究员
2012年4月12-16日第十四届全国核结构会议 湖州

2. I . Introduction
II. Theoretical model
III. Results and discussions
IV. Summary

3. Quadrupole deformation of the nuclear ground states
I. Introduction
Shapes of nuclei
Prolate
Oblate
Quadrupole deformation of the nuclear ground states
M. Girod, CEA Bruyères-le-Châtel
Few nuclei have oblate ground states (~86% are prolate in their ground state)
Phys Rev C64 (2001)

4. What’s the nature of the new isomer?
A new isomer with a half-life of 620 ±150 ns has been identified in 108Zr.
What’s the nature of the new isomer?
A tetrahedral
shape isomer?

5. The parity of the tetrahedral shape isomer is negative.
Ex>1MeV, J≥4
The parity of the tetrahedral shape isomer is negative.
N. Schunck et al., Phys. Rev. C 69, (R) (2004).

8. II. Theoretical model Projected shell model (PSM)
1. Multi-quasiparticle configuration
2. Angular momentum projection operator
3. Hamiltonian
K. Hara, Y. Sun, Int. J. Mod. Phys. E 4 (1995) 637

9. Triaxial projected shell model (TPSM)
1. Triaxial Nilsson Hamiltonian
2. Three-dimensional angular momentum projection
1). J. A. Sheikh and K. Hara, Phys.Rev.Lett. 82, 3968 (1999).
2). Y. Sun et al., Phys. Rev. C 61, (2000).

10. III. Results and discussions
The study of Zr by the projected shell model (PSM)
1. Moment of inertia
Y. X. Liu, Y. Sun, X. H. Zhou et al. Nucl. Phys. A, 2011, 858: 11-31

11. 2. Signature splitting in 1-qp bands

12. Nature of the isomer in very neutron-rich 108Zr
1. Calculated potential-energy surfaces for 108Zr and 110Zr
P. Möller et al., Atom. Data Nucl. Data Tables, 2012, 98:

14. 2. Oblate shape results

16. 2. Oblate shape with triaxiality

18. IV. Summary
♦ 1. The variation of moments of inertia in even–even nuclei
has been described as crossings of 2-qp bands with the
ground band.
♦ 2. By discussing the signature splitting, we have concluded
that the nuclei studied in this paper could be regarded as
axially symmetric systems.
♦ 3. To confirm whether this isomer has the tetrahedral shape or not,
the determination of the decay scheme including spins and
parities, and the measurement of the band structure above the
isomer, are required from future measurements.

19. Thanks