Shell model calculations for odd-mass A = 51–55 nuclei using a weak-coupling basis

1976 ◽  
Vol 54 (16) ◽  
pp. 1683-1691 ◽  
Author(s):  
H. G. Benson ◽  
I. P. Johnstone
Keyword(s):  
Shell Model ◽  
Weak Coupling ◽  
Coupling Model ◽  
Excitation Energies ◽  
Model Calculations ◽  
Neutron Hole

The excitation energies of states belonging to various n1-particle. n2-hole configurations relative to a 56,Ni core are calculated, using, when necessary, truncation based on a weak-coupling model. The calculations account for the occurrence of low-lying five-hole states in 53Mn, reproduce the bands of neutron–hole states observed in 53Cr and 53Fe, and predict the existence of low-lying four-hole states in 55Co.

Low-lying Negative-parity Levels of 17N and 18N

1984 ◽  
Vol 37 (1) ◽  
pp. 17 ◽  
Author(s):  
FC Barker
Keyword(s):  
Shell Model ◽  
Weak Coupling ◽  
Coupling Model ◽  
Negative Parity ◽  
Positive Parity ◽  
Model Calculations

On the basis of a weak-coupling model, adjustments are made to the interactions used in the full shell model calculations of Millener in order to fit the experimental energies of the low-lying negativeparity levels of 16N and of the low-lying positive-parity levels of 180 and 190 . The predicted energies of the low-lying negative-parity levels of 17N then agree better with experiment, while those for 18N lead to suggested spin assignments for the observed levels.

Resonances in the 15N(α,γ)19F Reaction Between Eα = 1.68 and 2.72 MeV

1972 ◽  
Vol 50 (20) ◽  
pp. 2428-2443 ◽  
Author(s):  
D. W. O. Rogers ◽  
R. P. Beukens ◽  
W. T. Diamond
Keyword(s):  
Shell Model ◽  
Weak Coupling ◽  
Coupling Model ◽  
Branching Ratios ◽  
Negative Parity ◽  
Angular Distributions ◽  
Model Calculations ◽  
Spin Parity ◽  
The Third

Using the 15N(α,γ)19F reaction, the properties of 6 levels between 5.3 and 6.2 MeV in 19F have been studied. In conjunction with previously reported restrictions on spins for these levels, measurements of branching ratios, radiative widths, and angular distributions have been used to make the following spin–parity assignments; 5618 keV, 3/2−; 5938 keV, 1/2+; 6070 keV, 7/2+; 6088 keV, 3/2−; 6160 keV, 7/2−. The properties of these levels and that at 5336 keV have been compared in detail to the various shell model calculations done for 19F. The properties of the third Jπ = 7/2+ level at 6.07 MeV can be used to clear up some of the confusion caused by the first two Jπ = 7/2+ levels in 19F and the properties of the Jπ = 3/2− levels confirm the fact that the weak coupling model does not explain the negative parity states outside the K = 1/2− band.

A weak-coupling model for the even Zn isotopes

1977 ◽  
Vol 55 (10) ◽  
pp. 909-915 ◽  
Author(s):  
T. Vo-Van ◽  
S. S. M. Wong
Keyword(s):  
Proton Transfer ◽  
Weak Coupling ◽  
Level Structure ◽  
Coupling Model ◽  
Transition Rates ◽  
Vibrational States ◽  
Model Calculations ◽  
Zinc Isotopes ◽  
Protons And Neutrons ◽  
Zn Isotopes

The low-lying structures of even zinc isotopes are studied as the weak coupling of vibrational states of protons and neutrons obtained from shell-model calculations. In spite of its simplicity, the model is capable of describing the known level structure and E2 transition rates as well as producing reliable two-proton transfer amplitudes. Extensions to include other even–even nuclei such as Ge, Se, and Kr are also discussed.

scholarly journals Realistic shell-model calculations for proton particle-neutron hole nuclei around132Sn

2002 ◽  
Vol 66 (6) ◽  
Author(s):  
L. Coraggio ◽  
A. Covello ◽  
A. Gargano ◽  
N. Itaco ◽  
T. T. S. Kuo
Keyword(s):  
Shell Model ◽  
Model Calculations ◽  
Neutron Hole

scholarly journals Energy Spectrum of 51V by the Intermediate Coupling Approach

1974 ◽  
Vol 27 (2) ◽  
pp. 289 ◽  
Author(s):  
Woon-Hyuk Chung
Keyword(s):  
Energy Spectrum ◽  
Shell Model ◽  
Strong Coupling ◽  
Energy Levels ◽  
Coupling Model ◽  
Intermediate Coupling ◽  
Rotational Model ◽  
Model Calculations ◽  
Coupling Approach ◽  
Intermediate Coupling Model

In recent years the nucleus 51 Y has been extensively studied, both experimentally by Horoshko et al. (1970), using the 48Ti(oc, py)51y reaction, and theoretically in terms of shell model calculations by many authors (McCullen et al. 1964; Horoshko et al. 1970; Lips and McEllistrem 1970). Mixed configuration shell model calculations by Lips and McEllistrem, in particular, have successfully reproduced the low-lying energy levels of5ly. However, strong coupling rotational model calculations by Malik and Scholz (1966) did not give satisfactory results. In the present work, the intermediate coupling unified model (Bohr and Mottelson 1953; Choudhury 1954) is applied to Sly. The purpose of this work is to show that the intermediate coupling model can successfully predict the low-lying energy levels of Sly.

Shell model description of the 0+ and 0− excited states in sd shell nuclei

2018 ◽  
Vol 96 (7) ◽  
pp. 774-778 ◽  
Author(s):  
M. Bouhelal ◽  
N. Saidane ◽  
S. Belaid ◽  
F. Haas
Keyword(s):  
Shell Model ◽  
Excited States ◽  
Ground State ◽  
Model Description ◽  
Excitation Energies ◽  
Model Calculations ◽  
The Future

The purpose of this work is to describe, in light of shell model calculations using the PSDPF interaction, the particular states with J = 0 in sd shell nuclei. These states are difficult to observe. It is well known that the ground state in even–even nuclei has Jπ = 0+ and therefore we are interested in describing their first excited [Formula: see text] states. We have also studied the first and second excited 0− states in all sd nuclei. The experimental and theoretical excitation energies of these states were confronted. This study allowed us to make predictions of the existence of [Formula: see text] and (or) [Formula: see text] states in nuclei, which do not possess these states, or to have an idea of their excitation energies for possible experiments in the future.

scholarly journals Gamow-Teller transitions of neutron-rich N = 82, 81 nuclei by shell-model calculations

2021 ◽  
Author(s):  
Noritaka Shimizu ◽  
Tomoaki Togashi ◽  
Yutaka Utsuno
Keyword(s):  
Shell Model ◽  
Large Scale ◽  
Β Decay ◽  
Excitation Energies ◽  
Pauli Blocking ◽  
Model Calculations ◽  
Model Hamiltonian ◽  
R Process ◽  
Gamow Teller ◽  
Valence Proton

Abstract β-decay half-lives of neutron-rich nuclei around N = 82 are key data to understand the r-process nucleosynthesis. We performed large-scale shell-model calculations in this region using a newly constructed shell-model Hamiltonian, and successfully described the low-lying spectra and half-lives of neutron-rich N = 82 and N = 81 isotones with Z = 42 − 49 in a unified way. We found that their Gamow-Teller strength distributions have a peak in the low-excitation energies, which significantly contributes to the half-lives. This peak, dominated by ν0g7/2 → π0g9/2 transitions, is enhanced on the proton deficient side because the Pauli-blocking effect caused by occupying the valence proton 0g9/2 orbit is weakened.

scholarly journals Statistical Fluctuations of Energy Spectra in the Isobar A = 68 Nuclei

2021 ◽  
pp. 496-504
Author(s):  
Adel. K. Hamoudi ◽  
Hayder A. Abd Alabas
Keyword(s):  
Shell Model ◽  
Matrix Theory ◽  
Energy Spectra ◽  
Nuclear Excitation ◽  
Excitation Energies ◽  
Gaussian Shape ◽  
Model Calculations ◽  
Level Densities ◽  
Statistical Fluctuations ◽  
Inert Core

Statistical fluctuations of nuclear energy spectra for the isobar A = 68 were examined by means of the random matrix theory together with the nuclear shell model. The isobar A = 68 nuclei are suggested to consist of an inert core of 56Ni with 12 nucleons in f5p-space (2p3/2, 1f5/2 and 2p1/2 orbitals). The nuclear excitation energies, required by this work, were obtained through performing f5p-shell model calculations using the isospin formalism f5pvh interaction with realistic single particle energies. All calculations of the present study were conducted using the OXBASH code. The calculated level densities were found to have a Gaussian shape. The distributions of level spacing P(s) and  statistic for the considered classes of states, obtained with full Hamiltonian of f5pvh (absence of the off-diagonal Hamiltonian) calculations, showed a chaotic (regular) behavior and coincided well with the distribution of Gaussian orthogonal ensemble (Poisson). Moreover, these distributions were independent of spin (J) and isospin (T)

Resonance (n, γ) measurements and weak-coupling model calculations of levels inSn119,Sn117, andSn115

1978 ◽  
Vol 18 (3) ◽  
pp. 1158-1177 ◽  
Author(s):  
S. Raman ◽  
R. F. Carlton ◽  
G. G. Slaughter ◽  
M. R. Meder
Keyword(s):  
Weak Coupling ◽  
Coupling Model ◽  
Model Calculations
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