Multiple octupole-type band structures in Th220: Reflection-asymmetric tidal waves?

The Th220 level scheme has been considerably extended from an experiment using the Mg26+Pt198 reaction at 128 MeV. The evaporation residues from this very fissile system were selected with the HERCULES detector system and residue-gated γ rays were measured with Gammasphere. The simplex feature (alternating-parity levels) persists up to the highest spins observed (23), but the nucleus exhibits a more vibrational-like behavior than the heavier Th isotopes. In addition, a doubling of the negative-parity, odd-spin states is seen as well as a staggering of the B(E1)/B(E2) ratios. A new interpretation based on a picture of tidal waves on a reflection-asymmetric nuclear surface is proposed

Parity doubling in Th219 and the onset of collectivity above N=126

Excited states in Th219 have been observed for the first time in an experiment using the Mg26+Pt198 reaction and evaporation-residue-gated γ-ray spectroscopy. Two structures of interlinked alternating-parity levels with simplex quantum numbers s=±i are observed, reminiscent of similar sequences in heavier odd-mass isotopes, but only three mass units away from the N=126 neutron closed shell. The emergence of quadrupole-octupole collectivity in this mass region and the trend for parity-doublet bands are discussed

Relativistic Continuum Hartree Bogoliubov Theory for Ground State Properties of Exotic Nuclei

The Relativistic Continuum Hartree-Bogoliubov (RCHB) theory, which properly takes into account the pairing correlation and the coupling to (discretized) continuum via Bogoliubov transformation in a microscopic and self-consistent way, has been reviewed together with its new interpretation of the halo phenomena observed in light nuclei as the scattering of particle pairs into the continuum, the prediction of the exotic phenomena -- giant halos in nuclei near neutron drip line, the reproduction of interaction cross sections and charge-changing cross sections in light exotic nuclei in combination with the Glauber theory, better restoration of pseudospin symmetry in exotic nuclei, predictions of exotic phenomena in hyper nuclei, and new magic numbers in superheavy nuclei, etc. Recent investigations on new effective interactions, the density dependence of the interaction strengthes, the RMF theory on the Woods-Saxon basis, the single particle resonant states, and the resonant BCS (rBCS) method for the pairing correlation, etc. are also presented in some details.Comment: 79 pages. Prog. Part. Nucl. Phys. (2005) in pres

Observation of new h9/2 and h11/2 bands in 187T1

The unfavoured signature of the rotation-aligned band associated with the prolate h9/2 structure in 187T1 has been identified. The deformation-aligned 11/2−[505] band is also confirmed and extended. While the alignment properties of the 11/2−[505] band seem to indicate that it has a similar magnitude of deformation as the prolate 186Hg core, the signature splitting at low spin, taken together with new self-consistent calculations, suggest that it may actually be triaxial with γ ≈ −180 near the bandhead