5,747 research outputs found
Asymptotics of neutron Cooper pair in weakly bound nuclei
Asymptotic form of neutron Cooper pair penetrating to the exterior of nuclear
surface is investigated with the Bogoliubov theory for the superfluid Fermions.
Based on a two-particle Schr\"{o}dinger equation governing the Cooper pair wave
function and systematic studies for both weakly bound and stable nuclei, the
Cooper pair is shown to be spatially correlated even in the asymptotic large
distance limit, and the penetration length of the pair condensate is revealed
to be universally governed by the two-neutron separation energy and
the di-neutron mass
Pair correlation of giant halo nuclei in continuum Skyrme-Hartree-Fock-Bogoliubov theory
The giant halos predicted in neutron-rich Zr isotopes with are
investigated by using the self-consistent continuum Skyrme
Hartree-Fock-Bogoliubov approach, in which the asymptotic behavior of continuum
quasiparticle states is properly treated by the Green's function method. We
study in detail the neutron pair correlation involved in the giant halo by
analyzing the asymptotic exponential tail of the neutron pair condensate (pair
density) in addition to that of the neutron particle density. The neutron
quasiparticle spectra associated with these giant halo nuclei are examined. It
is found that the asymptotic exponential tail of the neutron pair condensate is
dominated by non-resonant continuum quasiparticle states corresponding to the
scattering states with low asymptotic kinetic energy. This is in contrast to
the asymptotic tail of the neutron density, whose main contributions arise from
the resonant quasiparticle states corresponding to the weakly-bound
single-particle orbits and resonance orbits in the Hartree-Fock potential
Theoretical study of the decay-out spin of superdeformed bands in the Dy and Hg regions
Decay of the superdeformed bands have been studied mainly concentrating upon
the decay-out spin, which is sensitive to the tunneling probability between the
super- and normal-deformed wells. Although the basic features are well
understood by the calculations, it is difficult to precisely reproduce the
decay-out spins in some cases. Comparison of the systematic calculations with
experimental data reveals that values of the calculated decay-out spins scatter
more broadly around the average value in both the 150 and 190
regions, which reflects the variety of calculated tunneling probability in each
band.Comment: 6 pages 4 figures (30 PS files). To appear in Proc. of NS2000
(Nuclear Structure 2000) conf., at MSU, 15-19 Aug., 200
Representation Theory of The Algebra
We review the recent development in the representation theory of the
algebra. The topics that we concern are, Quasifinite
representation, Free field realizations, (Super) Matrix Generalization,
Structure of subalgebras such as algebra, Determinant formula,
Character formula. (Invited talk at ``Quantum Field Theory, Integrable Models
and Beyond", YITP, 14-17 February 1994. To appear in Progress of Theoretical
Physics Proceedings Supplement.)Comment: 36 pages, LaTeX, RIMS-990, YITP/K-1087, YITP/U-94-25, SULDP-1994-
Dynamics of a deformable self-propelled domain
We investigate the dynamical coupling between the motion and the deformation
of a single self-propelled domain based on two different model systems in two
dimensions. One is represented by the set of ordinary differential equations
for the center of gravity and two tensor variables characterizing deformations.
The other is an active cell model which has an internal mechanism of motility
and is represented by the partial differential equation for deformations.
Numerical simulations show a rich variety of dynamics, some of which are common
to the two model systems. The origin of the similarity and the difference is
discussed.Comment: 6 pages, 6 figure
Effects of a New Triple-alpha Reaction on X-ray Bursts of a Helium Accreting Neutron Star
The effects of a new triple- reaction rate (OKK rate) on the helium
flash of a helium accreting neutron star in a binary system have been
investigated. Since the ignition points determine the properties of a
thermonuclear flash of type I X-ray bursts, we examine the cases of different
accretion rates, , of helium from to , which could cover the
observed accretion rates. We find that for the cases of low accretion rates,
nuclear burnings are ignited at the helium layers of rather low densities. As a
consequence, helium deflagration would be triggered for all cases of lower
accretion rate than . We
find that OKK rate could be barely consistent with the available observations
of the X-ray bursts on the helium accreting neutron star. However this
coincidence is found to depend on the properties of crustal heating and the
neutron star model.We suggest that OKK rate would be reduced by a factor of
for K in the range of the observational errors.Comment: 10 pages, 4 figure
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