3,410 research outputs found
Collective Rotation of Tetrahedral Nuclei in the Cranking Model
The three-dimensional cranking model is used to investigate the microscopic
aspects of the rotation of nuclei with the tetrahedral symmetry. Two classes of
rotation axes are studied corresponding to two different discrete symmetries of
the rotating hamiltonian. Self-consistent Hartree-Fock-Bogoliubov calculations
show that the tetrahedral minimum remains remarkably stable until the first
single-particle crossing.Comment: Proceedings of the XII Nuclear Physics Workshop Pierre and Marie
Curie, October 2005. To be published in IJMP
HFODD (v2.08k): User's Guide
We describe the input data and installation procedures of the code HFODD
(v2.08k). The present write-up contains complete and comprehensive information
that has originally been given in five independent publications. It is enhanced
by the subject index and indexes of variables, input-data keywords,
subroutines, and files that are used in this user guide.Comment: 100 LaTeX pages, 1 EPS figure, Table 7 corrected, on-line-only
publication, see also http://www.fuw.edu.pl/~dobaczew/hfodd/hfodd.htm
Search for the Skyrme-Hartree-Fock Solutions for Chiral Rotation in N=75 Isotones
A search for the self-consistent solutions for the chiral rotational bands in
the N=75 isotones, 130Cs, 132La, 134Pr and 136Pm is performed within the
Skyrme-Hartree-Fock cranking approach using SKM* and SLy4 parametrizations. The
dependence of the solutions on the time-odd contributions in the energy
functional is studied. From among the considered four isotones, self-consistent
chiral solutions are obtained only in 132La. The microscopic calculations are
compared with the 132La experimental data and with results of a classical model
that contains all the mechanisms underlying the chirality of the collective
rotational motion. Strong similarities between the HF and classical model
results are found. The suggestion formulated earlier by the authors that the
chiral rotation cannot exist below a certain critical frequency is further
illustrated and discussed, together with the microscopic origin of a transition
from the planar to chiral rotation in nuclei. We also formulate the
separability rule by which the Tilted-Axis-Cranking solutions can be inferred
from three independent Principal-Axis-Cranking solutions corresponding to three
different axes of rotation.Comment: 23 LaTeX pages, 11 PostScript Figure
Nuclei with Tetrahedral Symmetry
We discuss a point-group-theory based method of searching for new regions of
nuclear stability. We illustrate the related strategy with realistic
calculations employing the tetrahedral and the octahedral point groups. In
particular, several nuclei in the Rare Earth region appear as excellent
candidates to study the new mechanism.Comment: 18 pages, 4 figures, submitted to International Journal of Modern
Physics
Hartree-Fock-Bogolyubov calculations for nuclei with tetrahedral deformation
Hartree-Fock-Bogolyubov solutions corresponding to the tetrahedral
deformation are found in six tetrahedrally doubly-magic nuclei. Values of the
beta32 deformation, depths of the tetrahedral minima, and their energies
relative to the co-existing quadrupole minima are determined for several
versions of the Skyrme force. Reduction of the tetrahedral deformation energies
by pairing correlations is quantitatively analysed. In light nuclei, shallow
tetrahedral minima are found to be the lowest in energy, while in heavy nuclei,
the minima are deeper but appear at a few MeV of excitation.Comment: 6 LaTeX pages, 2 PostScript figures, presented at the XII Nuclear
Physics Workshop, 21-25 September, Kazimierz Dolny, Polan
Heavy quarkonium hybrids from Coulomb gauge QCD
Using the non-relativisitc reduction of Coulomb gauge QCD we compute spectrum
of the low mass hybrid mesons containing a heavy quark-antiquark pair. The
gluon degrees of freedom are treated in the mean field approximation calibrated
to the gluelump spectrum. We discuss the role of the non-abelian nature of the
QCD Coulomb interaction in the ordering of the spin-parity levels.Comment: 12 pages, 6 figure
The Shears Mechanism in 142Gd in the Skyrme-Hartree-Fock Method with the Tilted-Axis Cranking
We report on the first Skyrme-Hartree-Fock calculations with the tilted-axis
cranking in the context of magnetic rotation. The mean field symmetries,
differences between phenomenological and self-consistent methods and the
generation of shears-like structures in the mean field are discussed.
Significant role of the time-odd spin-spin effective interaction is pointed
out. We reproduce the shears mechanism, but quantitative agreement with
experiment is rather poor. It may have to do with too large core polarization,
lack of pairing correlations or properties of the Skyrme force.Comment: Presented at the XXVII Mazurian Lakes School of Physics, September
2-9 2001, Krzyze, Poland, Submitted to Acta Physica Polonic
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