Cartesian-mesh Representation Research Articles

Systematic study of electric-dipole excitations with fully self-consistent Skyrme HF plus RPA from light-to-medium-mass deformed nuclei

We undertake a systematic calculation on electric-dipole responses of even-even nuclei for a wide mass region employing a fully self-consistent Hartree-Fock plus RPA approach. For an easy implementation of the fully self-consistent calculation, the finite-amplitude method which we have proposed recently is employed. We calculated dipole responses in Cartesian mesh representation, which can deal with deformed nuclei but do not include pairing correlation. The systematic calculation has reached Nickel isotopes. The calculated results show reasonable agreement for heavy nuclei while the average excitation energies are underestimated for light nuclei. We show a systematic comparison of the splitting of the peak energy with the ground-state deformation.

Light exotic nuclei studied with the parity-projected Hartree-Fock method

Calculation of the variation after parity projection is performed in 3D Cartesian mesh representation for ground and excited states of even-even magnesium isotopes. The full 3D angular momentum projection after the variation provides rotational spectra for deformed nuclei. The method takes account of a part of octupole and rotational correlations beyond the mean field. We show the positive-parity ground band and the lowest negative-parity excited band in each isotope. Properties of the ground-state bands are in a good agreement with experiments.

Hartree-Fock+BCS Approach to Unstable Nuclei with the Skyrme Force

We reanalyze the results of our extensive Hartree-Fock + BCS calculation from new points of view paying attention to the properties of unstable nuclei. The calculation has been done with the Skyrme SIII force for the ground and shape isomeric states of 1029 even-even nuclei ranging 2 <= Z <= 114. We also discuss the advantages of the employed three-dimensional Cartesian-mesh representation, especially on its remarkably high precision with apparently coarse meshes when applied to atomic nuclei. In Appendices we give the coefficients of finite-point numerical differentiation and integration formulae suitable for Cartesian mesh representation and elucidate the features of each formula and the differences from a method based on the Fourier transformation.

High-spin yrast structure of 32S suggested by symmetry-unrestricted, cranked Hartree–Fock calculations

The high-spin yrast structure of 32S is investigated by means of the cranked Skyrme–Hartree–Fock method in the three-dimensional Cartesian-mesh representation without imposing restrictions on spatial symmetries. The result suggests that (1) a crossover from the superdeformed to the hyperdeformed-like configurations takes place on the yrast line at angular momentum I≃24, which corresponds to the “band termination” point in the cranked harmonic-oscillator model, and (2) non-axial octupole deformations of the Y 31 type play an important role in the yrast states in the range 5≤I≤13.

Extensive Hartree-Fock+BCS calculation with Skyrme SIII force

We have performed deformed Hartree-Fock+BCS calculations with the Skyrme SIII force for the ground states of even-even nuclei with 2 <= Z <= 114 and N ranging from outside the proton drip line to beyond the experimental frontier in the neutron-rich side. We obtained spatially localized solutions for 1029 nuclei, together with the second minima for 758 nuclei. The single-particle wavefunctions are expressed in a three-dimensional Cartesian-mesh representation, which is suitable to describe nucleon skins, halos, and exotic shapes as well as properties of ordinary stable nuclei. After explaining some of the practical procedures of the calculations, we compare the resulting nuclear masses with experimental data and the predictions of other models. We also discuss the quadrupole (m=0, 2) and hexadecapole (m=0, 2, 4) deformations, the skin thicknesses, the halo radii, and the energy difference between the oblate and the prolate solutions. Our results can be obtained via computer network.

Deformed Hartree-Fock calculation of proton-rich nuclei

We perform Hartree-Fock+BCS calculations for even-even nuclei with 2 <= Z <= 82 and N ranging from outside the proton drip line to the experimental frontier on the neutron-rich side. The ground state solutions are obtained for 737 nuclei, together with shape-coexistence solutions for 480 nuclei. Our method features the Cartesian-mesh representation of single-particle wavefunctions, which is advantageous in treating nucleon skins and exotic shapes. The results are compared with those of the finite-range droplet model of Moller et al. as well as the experimental values.