16,402 research outputs found

    Deduction of the quantum numbers of low-lying states of 6-nucleon systems based on symmetry

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    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

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    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

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    For the spinor Bose-Einstein condensates both the total spin SS and its Z-component SZS_{Z} should be conserved. However, in existing theories, only the conservation of SzS_{z} has been taken into account. To remedy, this paper is the first attempt to take the conservation of both % S and SZS_{Z} into account. For this purpose, a total spin-state with the good quantum numbers SS and SZS_{Z} 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 23^{23}Na and % ^{87}Rb condensates have been studied, where the levels distinct in SS split. It was found that the level density is extremely dense in the bottom of the ground band of 23^{23}Na, i.e., in the vicinity of the ground state. On the contrary, for 87^{87}Rb, the levels are extremely dense in the top of the ground band,Comment: 7 page, 5 figure

    Categorification of quantum symmetric pairs I

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    We categorify a coideal subalgebra of the quantum group of sl2r+1\mathfrak{sl}_{2r+1} by introducing a 22-category \`a la Khovanov-Lauda-Rouquier, and show that self-dual indecomposable 11-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 O\mathcal{O} of type B/C.Comment: final version, to appear in Quantum Topolog

    Challenge on the Astrophysical R-process Calculation with Nuclear Mass Models

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    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 rr-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 ρω\rho-\omega meson mixing on the equation of state in isospin-asymmetric nuclear matter

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    We reexamine effects of the ρω\rho-\omega 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 ρω\rho-\omega 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 ρω\rho-\omega mixing. In this case, it is found that the symmetry energy is not only significantly softened by the ρω\rho-\omega mixing at supra-saturation densities, similar to the lowest-order ρω\rho-\omega 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 σ\sigma meson.Comment: Significant changes made. Accepted version to appear in PRC (2009

    First excited band of a spinor Bose-Einstein condensate

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    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 23^{23}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

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    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 Esym(ρ)E_{sym}(\rho) lead to significantly different predictions on several Esym(ρ)E_{sym}(\rho)-sensitive experimental observables. The momentum-dependence of the symmetry potential is thus critically important for investigating accurately the equation of state (EOS{\rm EOS}) 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

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    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.
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