- Bernstein, LA
- Cizewski, JA
- Jin, H
- Younes, W
- Henry, RG
- Farris, LP
- Charos, A
- Carpenter, MP
- Janssens, RV
- Khoo, TL
- Lauritsen, T
- Bearden, IG
- Ye, D
- Becker, JA
- Henry, EA
- Brinkman, MJ
- Hughes, JR
- Kuhnert, A
- Wang, TF
- Stoyer, MA
- Diamond, RM
- Stephens, FS
- Deleplanque, MA
- Macchiavelli, AO
- Lee, IY
- Cederwall, B
- Oliveira, JR
- Burde, J
- Fallon, P
- Duyar, C
- Draper, JE
- Rubel, E
- Vo, DT
- et al.
We have studied via in-beam -ray spectroscopy Po196 and Po198, which are the first neutron-deficient Po isotopes to exhibit a collective low-lying structure. The ratios of yrast state energies and the E2 branching ratios of transitions from non-yrast to yrast states are indicative of a low-lying vibrational structure. The onset of collective motion in these isotopes can be attributed to the opening of the neutron i13/2 orbital at N112 and the resulting large overlap between the two valence protons in the h9/2 orbital and the valence neutrons in the i13/2 orbital. © 1995 The American Physical Society.