965 research outputs found
Relationships between log N-log S and celestial distribution of gamma-ray bursts
The apparent conflict between log N-log S curve and isotropic celestial distribution of the gamma ray bursts is discussed. A possible selection effect due to the time profile of each burst is examined. It is shown that the contradiction is due to this selection effect of the gamma ray bursts
Mean-field approach to superdeformed high-spin states in 40Ca and neutron-rich 50S regions
With the use of the symmetry-unrestricted cranked SHF method in the 3D
coordinate-mesh representation, a systematic search for the SD and HD
rotational bands in the N=Z nuclei from 32S to 48Cr has been done, and SD and
HD solutions have been found in 32S, 36Ar, 40Ca, 44Ti, and in 36Ar, 40Ca, 44Ti,
48Cr, respectively. The SD band in 40Ca is found to be extremely soft against
both the axially symmetric (Y30) and asymmetric (Y31) octupole deformations.
Possible presense of SD states in neutron-rich sulfur isotopes from 46S to 52S
has also been investigated, and deformation properties of neutron skins both in
the ground and SD states are discussed.Comment: 10 pages including 9 ps figures, Talk at International Symposium on
"Frontiers of Collective Motion 2002", November 6-9, 2002, Univ. of Aizu,
Japa
Kakutani Dichotomy on Free States
Two quasi-free states on a CAR or CCR algebra are shown to generate
quasi-equivalent representations unless they are disjoint.Comment: 12 page
Superdeformed bands in neutron-rich Sulfur isotopes suggested by cranked Skyrme-Hartree-Fock calculations
On the basis of the cranked Skyrme-Hartree-Fock calculations in the
three-dimensional coordinate-mesh representation, we suggest that, in addition
to the well-known candidate 32S, the neutron-rich nucleus 36S and the drip-line
nuclei,48S and 50S, are also good candidates for finding superdeformed
rotational bands in Sulfur isotopes. Calculated density distributions for the
superdeformed states in 48S and 50S exhibit superdeformed neutron skinsComment: 18 pages including 10 ps figure
Mixed Representation RPA Calculation for Octupole Excitations on Superdeformed Sates in the 40Ca and Neutron-Rich Sulfur Regions
By means of the mixed representation RPA based on the Skyrme-Hartree-Fock
mean field, we investigate low-frequency octupole excitations built on the
superdeformed (SD) states in the N=Z nuclei around 40Ca and the neutron-rich
Sulfur isotopes. The RPA calculation is carried out fully self-consistently on
the three-dimensional Cartesian mesh in a box, and yields a number of
low-frequency octupole vibrations built on the SD states in 32S, 36Ar, 40Ca and
44Ti. In particular, a strongly collective K^\pi=1^- octupole vibration is
suggested to appear on top of the SD state in 40Ca. For 48,50S close to the
neutron drip line, we find that the low-lying state created by the excitation
of a single neutron from a loosely bound low Omega level to a high Omega
resonance level acquires an extremely strong octupole transition strength due
to the spatially very extended structure of the particle-hole wave functions.Comment: 22 pages, 7 figure
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