Related papers: Improvement of the extended P+QQ interaction by mo…
To study collective motion, the extended pairing plus $QQ$ force model proposed recently is applied to $A$=46, 48 and 50 nuclei in the $fp$ shell region. Exact shell model calculations in the truncated model space…
Variations in the nuclear mean-field, in neutron-rich nuclei, are investigated within the framework of the nuclear shell model. The change is identified to originate mainly from the monopole part of the effective two-body proton-neutron…
We carry out a study of the study of the $Q \cdot Q$ interaction in a model space which consists of several nucleons in an open shell and all $2 \hbar \omega$ excitations. This interaction is $ -t (X_o/2) Q \cdot Q$, where for t=1 we get…
An extended pairing plus QQ force model, which has been shown to successfully explain the nuclear binding energy and related quantities such as the symmetry energy, is applied to study the alpha-like four-nucleon correlations in 1f_{7/2}…
In this paper we present a systematic analysis on the average interaction between the last protons and neutrons in atomic nuclei, which can be extracted from the double differences of nuclear binding energies. The empirical average…
Novel simple properties of the monopole component of the effective nucleon-nucleon interaction are presented, leading to the so-called monopole-based universal interaction. Shell structures are shown to change as functions of $N$ and $Z$…
Effective field theories have been successful in describing nuclei up to the alpha particle but face significant challenges for larger nuclei due to leading-order instabilities. These issues can be addressed with the introduction of a fake…
The spectral distribution method with modified Kuo-Brown interaction is extended to the study of the upper half as well as to odd-A nuclei, of the fp shell. The calculations show similar success to that obtained for the lower half.
The effective interaction GXPF1 for shell-model calculations in the full $pf$ shell is tested in detail from various viewpoints such as binding energies, electro-magnetic moments and transitions, and excitation spectra. The semi-magic…
A systematic analysis of the $\alpha$ + core structure is performed in the ground state bands of even-even nuclei of the $22 \leq Z \leq 42$ region in terms of the Local Potential Model. The $\alpha$ + core interaction is described by the…
A Nilsson mean-field plus extended pairing interaction Hamiltonian with many-pair interaction terms is proposed. Eigenvalues of the extended pairing model are easy to obtain. Our investigation shows that one- and two-body interactions…
The nuclear shell model assumes an effective mean-field plus interaction Hamiltonian in a specific configuration space. We want to understand how various interaction matrix elements affect the observables, the collectivity in nuclei and the…
The recently-proposed effective shell-model interaction, the pairing-plus-multipole Hamiltonian with the monopole interaction obtained by empirical fits starting from the monopole-based universal force (PMMU), is systematically applied to…
Energy levels and electromagnetic properties of with $N=28\sim 30$ nuclides are studied in terms of a large-scale shell model calculation, which contains no newly adjusted parameters. The Kuo-Brown $G$-matrix interaction is shown to…
The validity of the approximations done in the mean field description of the quasi-elastic excitation of medium-heavy nuclei is discussed. A test of the reliability of the plane wave Born approximation is presented. The uncertainty related…
Starting from the microscopic low-momentum nucleon-nucleon interaction V{low k}, we present the first systematic shell model study of magnetic moments and magnetic dipole transition strengths of the basic low-energy one-quadrupole phonon…
We investigate the impact of isovector and isoscalar proton-neutron pairing correlations on the ground-state properties of even-even N=Z nuclei with mass numbers between A=16 and A=120. Nuclear mean fields are generated using the…
We introduce a group-theoretical extension of the Dicke model which describes an ensemble of two-level atoms interacting with a finite radiation field. The latter is described by a spin model whose main feature is that it possesses a…
Our main concern in this work is to show how higher shell admixtures affect the spectrum of a Q.Q interaction. We first review how, in the valence space, the familiar SU(3) result for the energy spectrum can be obtained using a coordinate…
We study global features of proton-neutron (p-n) interactions and symmetry energy over a wide range of nuclei, using a schematic model interaction with four forces proposed recently. Calculations are performed by the BCS approximation in…