16,615 research outputs found
Deduction of the quantum numbers of low-lying states of 6-nucleon systems based on symmetry
The inherent nodal structures of the wavefunctions of 6-nucleon systems have
been investigated. The existence of a group of six low-lying states dominated
by L=0 has been deduced. The spatial symmetries of these six states are found
to be mainly {4,2} and {2,2,2}.Comment: 8 pages, no figure
Labeling Workflow Views with Fine-Grained Dependencies
This paper considers the problem of efficiently answering reachability
queries over views of provenance graphs, derived from executions of workflows
that may include recursion. Such views include composite modules and model
fine-grained dependencies between module inputs and outputs. A novel
view-adaptive dynamic labeling scheme is developed for efficient query
evaluation, in which view specifications are labeled statically (i.e. as they
are created) and data items are labeled dynamically as they are produced during
a workflow execution. Although the combination of fine-grained dependencies and
recursive workflows entail, in general, long (linear-size) data labels, we show
that for a large natural class of workflows and views, labels are compact
(logarithmic-size) and reachability queries can be evaluated in constant time.
Experimental results demonstrate the benefit of this approach over the
state-of-the-art technique when applied for labeling multiple views.Comment: VLDB201
Ground Band and a Generalized GP-equation for Spinor Bose-Einstein Condensates
For the spinor Bose-Einstein condensates both the total spin and its
Z-component should be conserved. However, in existing theories, only
the conservation of has been taken into account. To remedy, this paper
is the first attempt to take the conservation of both and into
account. For this purpose, a total spin-state with the good quantum numbers
and is introduced in the trial wave function, thereby a generalized
Gross-Pitaevskii equation has been derived. With this new equation, the ground
bands of the Na and Rb condensates have been studied, where the
levels distinct in split. It was found that the level density is extremely
dense in the bottom of the ground band of Na, i.e., in the vicinity of
the ground state. On the contrary, for Rb, the levels are extremely
dense in the top of the ground band,Comment: 7 page, 5 figure
Categorification of quantum symmetric pairs I
We categorify a coideal subalgebra of the quantum group of
by introducing a -category \`a la
Khovanov-Lauda-Rouquier, and show that self-dual indecomposable -morphisms
categorify the canonical basis of this algebra. This allows us to define a
categorical action of this coideal algebra on the categories of modules over
cohomology rings of partial flag varieties and on the BGG category
of type B/C.Comment: final version, to appear in Quantum Topolog
Challenge on the Astrophysical R-process Calculation with Nuclear Mass Models
Our understanding of the rapid neutron capture nucleosynthesis process in
universe depends on the reliability of nuclear mass predictions. Initiated by
the newly developed mass table in the relativistic mean field theory (RMF), in
this paper the influence of mass models on the -process calculations is
investigated assuming the same astrophysical conditions. The different model
predictions on the so far unreachable nuclei lead to significant deviations in
the calculated r-process abundances.Comment: 3 pages, 3 figure
Effects of medium-induced meson mixing on the equation of state in isospin-asymmetric nuclear matter
We reexamine effects of the meson mixing mediated by nucleon
polarizations on the symmetry energy in isospin-asymmetric nuclear matter.
Taking into account the rearrangement term neglected in previous studies by
others, we evaluate the mixing angle in a novel way within the
Relativistic Mean-Field Models with and without chiral limits. It is found that
the symmetry energy is significantly softened at high densities contrary to the
finding in earlier studies. As the first step of going beyond the lowest-order
calculations, we also solve the RPA equation for the mixing. In
this case, it is found that the symmetry energy is not only significantly
softened by the mixing at supra-saturation densities, similar to
the lowest-order mixing, but interestingly also softened at
subsaturation densities. In addition, the softening of the symmetry energy at
subsaturation densities can be partly suppressed by the nonlinear
self-interaction of the meson.Comment: Significant changes made. Accepted version to appear in PRC (2009
First excited band of a spinor Bose-Einstein condensate
The analytical expression of the fractional parentage coefficients for the
total spin-states of a spinor N-boson system has been derived. Thereby an
S-conserved theory for the spinor Bose-Einstein condensation has been proposed.
A set of equations has been established to describe the first excited band of
the condensates. Numerical solution for Na has been given as an example.Comment: 6 pages, 3 figure
Momentum dependence of the symmetry potential and nuclear reactions induced by neutron-rich nuclei at RIA
Effects of the momentum-dependence of the symmetry potential in nuclear
reactions induced by neutron-rich nuclei at RIA energies are studied using an
isospin- and momentum-dependent transport model. It is found that symmetry
potentials with and without the momentum-dependence but corresponding to the
same density-dependent symmetry energy lead to significantly
different predictions on several -sensitive experimental
observables. The momentum-dependence of the symmetry potential is thus
critically important for investigating accurately the equation of state () and novel properties of dense neutron-rich matter at RIA.Comment: Rapid Communication, Phys. Rev. C in pres
Isospin dependence of nucleon emission and radial flow in heavy-ion collisions induced by high energy radioactive beams
Using an isospin- and momentum-dependent transport model we study the
emission of free nucleons and the nuclear radial flow in central heavy-ion
collisions induced by high energy radioactive beams. The midrapidity
neutron/proton ratio and its transverse momentum dependence are found very
sensitive to the high density behavior of nuclear symmetry energy. The nuclear
radial flow, however, depends only weakly on the symmetry energy.Comment: 13 pages including 6 figures, submitted to Phys. Rev.
- …