Tidal Waves and Onset of Collectivity above N = 126

W. Reviol , D.G. Sarantites , X. Chen , M. Montero , O.L. Pechenaya , J. Snyder , R.V.F. Janssens , M.P. Carpenter , C.J. Chiara , T.L. Khoo , T. Lauritsen , C.J. Lister , D. Seweryniak , S. Zhu , K. Hauschild (1) , A. Lopez-Martens (1) , D.J. Hartley , S. Frauendorf

1 CSNSM - Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse

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 Th-220 nucleus and the neighboring Ra-218 and Th-219 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.

Mots clés: NUCLEI; SPECTROSCOPY; GAMMASPHERE; OCTUPOLE; STATES

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

W. Reviol, D.G. Sarantites, X. Chen, M. Montero, O.L. Pechenaya, et al.. Tidal Waves and Onset of Collectivity above N = 126. Conference on Nuclear Physics - Extremes of the Nuclear Landscape, Aug 2010, Zakopane, Poland. pp.671-680, ⟨10.5506/APhysPolB.42.671⟩. ⟨in2p3-00596541⟩