1. Wobbling Motion in Triaxial Superdeformed Nuclei
china_matsuzaki.ppt
2019/4/26
Wobbling Motion in Triaxial Superdeformed Nuclei
Masayuki Matsuzaki
Fukuoka University of Education
based on MM, Shimizu and Matsuyanagi,
PR C65, (R) and C69,

2. Shell gap  stable configurations
Superdeformation
single particle energy
2:1 2
deformation

3. Shell gaps in Nilsson diagram at
neutron
proton
 Suggest triaxial superdeformation (TSD) around

4. γ deformation in rotating systems

5. R.Bengtsson, http://www.matfys.lth.se/~ragnar/TSD-ensyst.html
-----γ～+20゜
TSD 2 ND
-----γ～-20゜
TSD 2
R.Bengtsson,

6. TSD (γ>0) TSD(γ<0) ND
R.Bengtsson,

7. Triaxial  rotations about 3 axes are possible  wobbling
“phonon”
rot

8. TSD1: 0 phonon (yrast)
TSD2: 1 phonon
TSD3: 2 phonon
TSD4: another conf.

9. γ～+20゜ contradicts irrotational ?

10. Rotating odd-mass nucleus can be regarded as “rotor plus 1qp”
1qp also carries moment of inertia
Thus, inertia of the whole system should be considered (in contrast to PRM)

12. Irrotational + QP align   wobbling allowed

14. (If inertia are constant,
163 Lu
Not ∝ω
rot !
Automatically ω
rot
-dependent
(If inertia are constant, )

15. 163 Lu
Extremely collective
as an RPA solution
but …

16. Parameterizations of triaxial deformation
γ(dens)=20°rather than γ(Nils)=20°
resolves discrepancy in B(E2) ratio

17. TSD1: 0 phonon (yrast)
TSD2: 1 phonon
TSD3: 2 phonon
TSD4: another conf.

18. indicates softening of potential
2 phonon
1 phonon
indicates softening of potential
 Removal of 1qp makes wobbling unstable

19. Summary
ΔJx from QP alignment superimposed on irrot.-like inertia brings Jx > Jy for γ>0 --- This assures the existence of wobbling exc.
Wobbling mode in 163Lu is naturally described semi-quantitatively in terms of RPA
Anharmonicity of 2-phonon states suggests softening of potential surface