18,941 research outputs found
Benchmarks of the full configuration interaction, Monte Carlo shell model, and no-core full configuration methods
We report no-core solutions for properties of light nuclei with three
different approaches in order to assess the accuracy and convergence rates of
each method. Full configuration interaction (FCI), Monte Carlo shell model
(MCSM) and no core full configuration (NCFC) approaches are solved separately
for the ground state energy and other properties of seven light nuclei using
the realistic JISP16 nucleon-nucleon interaction. The results are consistent
among the different approaches. The methods differ significantly in how the
required computational resources scale with increasing particle number for a
given accuracy.Comment: 19 pages, 14 figures, 6 table
Novel Extrapolation Method in the Monte Carlo Shell Model
We propose an extrapolation method utilizing energy variance in the Monte
Carlo shell model in order to estimate the energy eigenvalue and observables
accurately. We derive a formula for the energy variance with deformed Slater
determinants, which enables us to calculate the energy variance efficiently.
The feasibility of the method is demonstrated for the full -shell
calculation of Ni, and the applicability of the method to a system
beyond current limit of exact diagonalization is shown for the
+-shell calculation of Ge.Comment: 4 pages, 4figure
Lambda(1405) as a Resonance in the Baryon-Meson Scattering Coupled to the q^3 State in a Quark Model
In order to describe Lambda(1405) as a resonance in the baryon-meson
scattering, we have investigated q^3-q qbar scattering system with the
flavor-singlet q^3 (0s)^2(0p) state (the Lambda^1 pole). The scattering is
treated by the quark cluster model (QCM). The Lambda^1 pole is treated as a
bound state embedded in the continuum. We found that the peak appears below the
N Kbar threshold in the spin one half, isospin 0 channel even if the mass of
the Lambda^1 pole is above the threshold. This peak disappears when the
coupling to the Lambda^1 pole is switched off. To use the observed hadron mass
in the kinetic part of QCM is also found to be important to reproduce a peak
just below the N Kbar threshold.Comment: 16 pages and 7 figure
Ingredients of nuclear matrix element for two-neutrino double-beta decay of 48Ca
Large-scale shell model calculations including two major shells are carried
out, and the ingredients of nuclear matrix element for two-neutrino double beta
decay are investigated. Based on the comparison between the shell model
calculations accounting only for one major shell (-shell) and those for two
major shells (-shell), the effect due to the excitation across the two
major shells is quantitatively evaluated.Comment: To appear in J. Phys. Soc. Conf. Proc. (ARIS2014); for ver.2, Fig.1
is revise
High-K Precession modes: Axially symmetric limit of wobbling motion
The rotational band built on the high-K multi-quasiparticle state can be
interpreted as a multi-phonon band of the precession mode, which represents the
precessional rotation about the axis perpendicular to the direction of the
intrinsic angular momentum. By using the axially symmetric limit of the
random-phase-approximation (RPA) formalism developed for the nuclear wobbling
motion, we study the properties of the precession modes in W; the
excitation energies, B(E2) and B(M1) values. We show that the excitations of
such a specific type of rotation can be well described by the RPA formalism,
which gives a new insight to understand the wobbling motion in the triaxial
superdeformed nuclei from a microscopic view point.Comment: 14 pages, 8 figures (Spelling of the authors name was wrong at the
first upload, so it is corrected
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