TIDAL WAVES AND ONSET OF COLLECTIVITY ABOVE N = 126.

Authors :: Reviol, W.
Sarantites, D. G.
Chen, X.
Montero, M.
Pechenaya, O. L.
Snyder, J.
Janssens, R. V. F.
Carpenter, M. P.
Chiara, C. J.
Khoo, T. L.
Lauritsen, T.
Lister, C. J.
Seweryniak, D.
Zhu, S.
Hauschild, K.
Lopez-Martens, A.
Hartley, D. J.
Frauendorf, S.
Source :: Acta Physica Polonica B; Mar/Apr2011, Vol. 42 Issue 3/4, p671-680, 10p
Publication Year :: 2011
Abstract: Recent experiments in the actinide region, using Gammasphere and the evaporation residue detector HERCULES, have covered the territory between N = 126 and the center of static octupole deformation at N = 134. The <superscript>220</superscript>Th nucleus and the neighboring <superscript>218</superscript>Ra and <superscript>219</superscript>Th nuclei mark the emergence of quadrupole-octupole collectivity in this mass region. Their octupole bands have B(E1)/B(E2) ratios which are typical for the region, but the level spacings do not concur with a rotational-like behavior. In addition, a spin-dependent staggering of the B(E1)/B(E2) ratios is evident. These features can be described, based on a phonon picture, by a constant-frequency tidal-wave mode for a reflection-asymmetric nuclear surface. [ABSTRACT FROM AUTHOR]