Onset of collectivity in neutron deficientPo196,198

L. A. Bernstein, J. A. Cizewski, H.-Q. Jin, W. Younes, R. G. Henry, L. P. Farris, A. Charos, M. P. Carpenter, R. V. F. Janssens, T. L. Khoo, T. Lauritsen, I. G. Bearden (+21 others)
1995 Physical Review C  
We have studied via in-beam $\gamma$-ray spectroscopy $^{196}$Po and $^{198}$Po, 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 i$_{13/2}$ orbital at N$\approx$112 and the resulting large
more » ... esulting large overlap between the two valence protons in the h$_{9/2}$ orbital and the valence neutrons in the i$_{13/2}$ orbital.
doi:10.1103/physrevc.52.621 pmid:9970552 fatcat:5nn2f2pcwvgztnatk4gwiodxdi