68 research outputs found
Isospin corrections for superallowed Fermi beta decay in self-consistent relativistic random phase approximation approaches
Self-consistent random phase approximation (RPA) approaches in the
relativistic framework are applied to calculate the isospin symmetry-breaking
corrections for the superallowed transitions. It is
found that the corrections are sensitive to the proper treatments of
the Coulomb mean field, but not so much to specific effective interactions.
With these corrections , the nucleus-independent
values are obtained in combination with the experimental values in the
most recent survey and the improved radiative corrections. It is found that the
constancy of the values is satisfied for all effective
interactions employed. Furthermore, the element and unitarity of the
Cabibbo-Kobayashi-Maskawa matrix are discussed.Comment: 7 pages, 2 figures, 4 table
RPA Correlations and Nuclear Densities in Relativistic Mean Field Approach
The relativistic mean field approach (RMF) is well known for describing
accurately binding energies and nucleon distributions in atomic nuclei
throughout the nuclear chart. The random phase approximation (RPA) built on top
of the RMF is also a good framework for the study of nuclear excitations. Here,
we examine the consequences of long range correlations brought about by the RPA
on the neutron and proton densities as given by the RMF approach.Comment: 15 pages, 13 figure
Fine structure of charge-exchange spin-dipole excitations in O
The charge-exchange spin-dipole (SD) excitations for both and
channels in O are investigated in the fully self-consistent random phase
approximation based on the covariant density functional theory. The fine
structure of SD excitations in the most up-to-date O()F experiment is excellently reproduced without any readjustment in
the functional. The characteristics of SD excitations are understood with the
delicate balance between the - and -meson fields via the
exchange terms. The fine structure of SD excitations for
O()N channel is predicted for future experiments.Comment: 5 pages, 4 figure
Finite-amplitude method: An extension to the covariant density functionals
The finite-amplitude method (FAM) is one of the most promising methods for
optimizing the computational performance of the random-phase approximation
(RPA) calculations in deformed nuclei. In this report, we will mainly focus on
our recent progress in the self-consistent relativistic RPA established by
using the FAM. It is found that the effects of Dirac sea can be taken into
account implicitly in the coordinate-space representation and the rearrangement
terms due to the density-dependent couplings can be treated without extra
computational costs.Comment: 5 pages, 2 figures, Proceedings of the 20th Nuclear Physics Workshop
"Marie & Pierre Curie", Kazimierz, Poland, 25-29 September, 201
Feasibility of the finite amplitude method in covariant density functional theory
Self-consistent relativistic random-phase approximation (RPA) in the radial
coordinate representation is established by using the finite amplitude method
(FAM). Taking the isoscalar giant monopole resonance in spherical nuclei as
example, the feasibility of the FAM for the covariant density functionals is
demonstrated, and the newly developed methods are verified by the conventional
RPA calculations. In the present relativistic RPA calculations, the effects of
the Dirac sea can be automatically taken into account in the coordinate-space
representation. The rearrangement terms due to the density-dependent couplings
can be implicitly calculated without extra computational costs in both
iterative and matrix FAM schemes.Comment: 12 pages, 5 figure
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