58,108 research outputs found
A comparative study of super- and highly-deformed bands in the A ~ 60 mass region
Super- and highly-deformed rotational bands in the A ~ 60 mass region are
studied within cranked relativistic mean field theory and the
configuration-dependent shell-correction approach based on the cranked Nilsson
potential. Both approaches describe the experimental data well. Low values of
the dynamic moments of inertia J^(2) compared with the kinematic moments of
inertia J^(1) seen both in experiment and in calculations at high rotational
frequencies indicate the high energy cost to build the states at high spin and
reflect the limited angular momentum content in these configurations.Comment: 11 pages, 4 PostScript figures, Latex, uses 'epsf', submitted to
Phys. Lett.
Classical Analysis of Phenomenological Potentials for Metallic Clusters
The classical trajectories of single particle motion in a Wodds-Saxon and a
modified Nilsson potential are studied for axial quadrupole deformation. Both
cases give rise to chaotic behaviour when the deformation in the Woods-Saxon
and the l**2 term in the modified Nilsson potential are turned on. Important
similarities, in particular with regard to the shortest periodic orbits, have
been found.Comment: 9 pages LaTex + 4 figures available via e-mail requests from the
authors, to appear in Phys.Rev.Let
Triaxial projected shell model approach
The projected shell model analysis is carried out using the triaxial
Nilsson+BCS basis. It is demonstrated that, for an accurate description of the
moments of inertia in the transitional region, it is necessary to take the
triaxiality into account and perform the three-dimensional angular-momentum
projection from the triaxial Nilsson+BCS intrinsic wavefunction.Comment: 9 pages, 2 figure
Rotation and alignment of high- orbitals in transfermium nuclei
The structure of nuclei with is investigated systematically by the
Cranked Shell Model (CSM) with pairing correlations treated by a
Particle-Number Conserving (PNC) method. In the PNC method, the particle number
is conserved and the Pauli blocking effects are taken into account exactly. By
fitting the experimental single-particle spectra in these nuclei, a new set of
Nilsson parameters ( and ) is proposed. The experimental kinematic
moments of inertia and the band-head energies are reproduced quite well by the
PNC-CSM calculations. The band crossing, the effects of high- intruder
orbitals and deformation are discussed in detail.Comment: To appear in the Proceedings of the International Nuclear Physics
Conference (INPC2013), June 2-7, 2013, Florence, Ital
Neutron shell structure and deformation in neutron-drip-line nuclei
Neutron shell-structure and the resulting possible deformation in the
neighborhood of neutron-drip-line nuclei are systematically discussed, based on
both bound and resonant neutron one-particle energies obtained from spherical
and deformed Woods-Saxon potentials. Due to the unique behavior of weakly-bound
and resonant neutron one-particle levels with smaller orbital angular-momenta
, a systematic change of the shell structure and thereby the change of
neutron magic-numbers are pointed out, compared with those of stable nuclei
expected from the conventional j-j shell-model. For spherical shape with the
operator of the spin-orbit potential conventionally used, the levels
belonging to a given oscillator major shell with parallel spin- and
orbital-angular-momenta tend to gather together in the energetically lower half
of the major shell, while those levels with anti-parallel spin- and
orbital-angular-momenta gather in the upper half. The tendency leads to a
unique shell structure and possible deformation when neutrons start to occupy
the orbits in the lower half of the major shell. Among others, the neutron
magic-number N=28 disappears and N=50 may disappear, while the magic number
N=82 may presumably survive due to the large spin-orbit splitting for
the orbit. On the other hand, an appreciable amount of energy gap
may appear at N=16 and 40 for spherical shape, while neutron-drip-line nuclei
in the region of neutron number above N=20, 40 and 82, namely N
21-28, N 41-54, and N 83-90, may be quadrupole-deformed
though the possible deformation depends also on the proton number of respective
nuclei.Comment: 16 pages, 4 figure
Reaction cross sections of the deformed halo nucleus 31Ne
Using the Glauber theory, we calculate reaction cross sections for the
deformed halo nucleus Ne. To this end, we assume that the Ne
nucleus takes the Ne + structure. In order to take into account the
rotational excitation of the core nucleus Ne, we employ the
particle-rotor model (PRM). We compare the results to those in the adiabatic
limit of PRM, that is, the Nilsson model, and show that the Nilsson model works
reasonably well for the reaction cross sections of Ne. We also
investigate the dependence of the reaction cross sections on the ground state
properties of Ne, such as the deformation parameter and the p-wave
component in the ground state wave function.Comment: 7 pages, 6 eps figure
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