scholarly journals An analytical formula for proton momentum distribution in nuclei with A>4

2019 ◽  
Vol 10 ◽  
pp. 248
Author(s):  
G. S. Anagnostatos ◽  
A. N. Antonov ◽  
J. Giapitzakis ◽  
P. Ginis ◽  
S. E. Massen ◽  
...  
Keyword(s):  
Experimental Data ◽  
Shell Model ◽  
Momentum Distribution ◽  
Analytical Formula ◽  
Nucleon Nucleon ◽  
Exotic Nuclei ◽  
Wave Functions ◽  
Proton Momentum ◽  
Correlation Effects ◽  
Hartree Fock

A successful analytical formula for the proton momentum distribution in all nuclei with A>4 accounting for nucleon-nucleon correlation effects, is presented. In this formula the Isomorphic Shell Model wave functions are employed, which are readily available for all nuclei all the way up to 2 0 8Pb. However, other wave functions (e.g., shell model or Hartree-Fock) could be used with almost equivalent results. Available experimental data for 4He, 1 2C and 5 6Fe and predictions of other theories, e.g., for 4 0Ca, are used for comparison of the predictions of the present formula. A reservation is kept concerning the validity of this formula for the momentum distribution of exotic nuclei.

The octupole deformation of 143Ba

2015 ◽  
Vol 24 (11) ◽  
pp. 1550081 ◽  
Author(s):  
Yong-Jing Chen ◽  
Yong-Shou Chen ◽  
Zao-Chun Gao ◽  
Ya Tu
Keyword(s):  
Experimental Data ◽  
Shell Model ◽  
Ground State ◽  
Wave Functions ◽  
Rotational Bands ◽  
Octupole Deformation ◽  
Quantum Numbers

Based on existence of the octupole deformation in the intrinsic states, the experimentally observed four rotational bands in [Formula: see text]Ba have been well reproduced by the reflection asymmetric shell model (RASM) calculations. Through the analysis of the calculated RASM wave functions, the intrinsic configuration of the observed rotational bands has been assigned as the octupole deformed neutron [Formula: see text] orbit, which is just located below the [Formula: see text] shell gap. The calculated results supported the ground state octupole deformation and the purity of the simplex quantum numbers [Formula: see text] in [Formula: see text]Ba. In addition, the calculated [Formula: see text] values are in agreement with experimental data, and further support the octupole deformation in [Formula: see text]Ba.

Shell model and Hartree–Fock calculations for some exotic nuclei

2015 ◽  
Vol 24 (12) ◽  
pp. 1550099 ◽  
Author(s):  
Ali A. Alzubadi ◽  
Nabeel F. Latooffi ◽  
R. A. Radhi
Keyword(s):  
Shell Model ◽  
Mass Density ◽  
Effective Interaction ◽  
Mean Field ◽  
Form Factors ◽  
Field Approximation ◽  
Exotic Nuclei ◽  
Mean Field Approximation ◽  
Hartree Fock ◽  
Density Distributions

Mass density distributions, the associated nuclear radii and elastic electron scattering form factors of light exotic nuclei, [Formula: see text]Li, [Formula: see text]Be, [Formula: see text]Be and 8B have been calculated using shell model (SM) and Hartree–Fock (HF) methods. We consider truncated spsdpf no core SM and WBP two-body effective interaction to give the SM wave functions. The single-particle matrix elements have been calculated with Skyrme-Hartree–Fock (SHF) potential with different parametrizations. It is shown that the calculated densities and form factors are in fine agreement with experimental data. This agreement can be interpreted as the adequacy of the HF mean-field approximation for exotic nuclei.

MICROSCOPIC NEUTRON OPTICAL POTENTIAL IN THE ENERGY REGION 65–225 MeV

2011 ◽  
Vol 20 (09) ◽  
pp. 2017-2026 ◽  
Author(s):  
SYED RAFI ◽  
W. HAIDER
Keyword(s):  
Experimental Data ◽  
Energy Region ◽  
Optical Potential ◽  
Nucleon Nucleon ◽  
Scattering Data ◽  
Potential Analysis ◽  
Hartree Fock ◽  
Empirical Potentials ◽  
Microscopic Optical Potential ◽  
First Time

In the present work, we report a microscopic optical potential analysis of the extensive neutron elastic scattering data from 12 C , 40 Ca and 208 Pb in the 65–225 MeV energy region. Brueckner–Hartree–Fock method has been used to calculate the optical potential, where one requires internucleon potential to calculate reaction matrices which are then folded over the nucleon densities in the target nuclei. We report the predictions of the calculated potential using Argonne v-18 and Urbana v-14 local nucleon–nucleon potentials. The modern potential v-18 has been used for the first time to calculate the nucleon–nucleus optical potential. We also compare our predictions with the empirical potentials. The results indicate that the predictions of our microscopic potential are in better agreement with the experimental data as compared with the empirical global optical potentials.

Schalenmodellrechnungen beim Kern O18 mit geschwindigkeitsabhängigen Zwei-Teilchen-Potentialen

1967 ◽  
Vol 22 (4) ◽  
pp. 415-421
Author(s):  
Hans Grote
Keyword(s):  
Experimental Data ◽  
Harmonic Oscillator ◽  
Shell Model ◽  
Interaction Potential ◽  
Ground State ◽  
Wave Functions ◽  
Absolute Position ◽  
Model Calculations ◽  
The Core ◽  
Free Parameters

The energies of the low lying levels and the absolute position of the ground state of the nucleus O18 are calculated using five velocity-dependent potentials. The calculation is based on the shell model with two outer neutrons in the potential of the Ο16 core. The interaction potential as well as the core potential are fitted to experimental data, leaving no free parameters in the final result.The wave functions of the harmonic oscillator are used in each case of the five velocity-dependent potentials. An additional computation is carried out using one of these potentials and taking into account the perturbation of the wave functions. It turns out that, for satisfactory application of the velocity-dependent potentials in shell model calculations, this perturbation should be considered.

Hartree-Fock Cluster Computations for Ionic Crystals

1985 ◽  
Vol 63 ◽  
Author(s):  
J. M. Vail ◽  
R. Pandey
Keyword(s):  
Shell Model ◽  
Alkaline Earth ◽  
Optical Transition ◽  
Alkali Halides ◽  
Wave Functions ◽  
Ionic Crystals ◽  
Perfect Lattice ◽  
Hartree Fock ◽  
Quantum Cluster ◽  
Model Lattice

ABSTRACTThe ICECAP code is applied to charged and uncharged color centers in alkali halides and alkaline-earth oxides, to test the usefulness of complete-cation pseudopotentials for reproducing the cluster boundary conditions. The physical model includes consistency up to electrostatic octupole order between the Hartree-Fock cluster and the surrounding infinite shell-model lattice. The total energy of the system is determined variationally, including distortion and polarization of the cluster and lattice, and LCAO-MO gaussian-localized cluster wave functions. Electronic states with the lattice unrelaxed are also analysed, yielding color-center optical transition energies. Furthermore, consistency between quantum (cluster) and classical (shell-model) descriptions of the perfect lattice is tested.

Charge-Exchange Scattering of Pions on 14N

1971 ◽  
Vol 49 (13) ◽  
pp. 1826-1827 ◽  
Author(s):  
Arlene P. Maclin ◽  
J. M. Eisenberg
Keyword(s):  
Experimental Data ◽  
Shell Model ◽  
Charge Exchange ◽  
Cross Sections ◽  
Theoretical Calculations ◽  
Impulse Approximation ◽  
Wave Functions ◽  
Exchange Scattering ◽  
Low Amplitude ◽  
Model Formalism

Cross sections for the reaction 14N(π+,π0)14O are calculated near the (3, 3) resonance using the impulse approximation together with the Chew–Low amplitude in the framework of a two-hole shell model formalism. Various sets of wave functions are used and comparisons are made with existing experimental data and other theoretical calculations.

scholarly journals Electromagnetic multipole of positive and negative parity states in 24Mg by elastic and inelastic electron scattering

2019 ◽  
Vol 17 (42) ◽  
pp. 27-41
Author(s):  
NOORI S. Manie
Keyword(s):  
Experimental Data ◽  
Shell Model ◽  
Electron Scattering ◽  
Single Particle ◽  
Transition Probabilities ◽  
Form Factors ◽  
Negative Parity ◽  
Inelastic Electron ◽  
Hartree Fock ◽  
Inelastic Electron Scattering

In the present work, the nuclear shell model with Hartree–Fock (HF) calculations have been used to investigate the nuclear structure of 24Mg nucleus. Particularly, elastic and inelastic electron scattering form factors and transition probabilities have been calculated for low-lying positive and negative states. The sd and sdpf shell model spaces have been used to calculate the one-body density matrix elements (OBDM) for positive and negative parity states respectively. Skyrme-Hartree-Fock (SHF) with different parameterizations has been tested with shell model calculation as a single particle potential for reproducing the experimental data along with a harmonic oscillator (HO) and Woods-Saxon (WS) single-particle potentials. The effect of the nuclear effective charge has been implemented via using different folding models; valance, Tassie and Bohr-Mottelson. The evaluated results have been discussed and compared with available experimental data.

Study of the nuclear structure of some exotic nuclei using nonrelativistic and relativistic mean-field methods

2020 ◽  
pp. 2050090
Author(s):  
Abbas A. Allami ◽  
Ali A. Alzubadi
Keyword(s):  
Density Dependence ◽  
Shell Model ◽  
Nuclear Structure ◽  
Cross Section ◽  
Reaction Cross Section ◽  
Reaction Cross ◽  
Exotic Nuclei ◽  
Meson Exchange ◽  
Field Methods ◽  
Hartree Fock

The nuclear shell model with the Skyrme–Hartree–Fock (SHF), as a nonrelativistic approach, and the Relativistic Hartree–Fock–Bogoliubov (RHFB) methods have been used to study the nuclear structure of some exotic nuclei at the proton and neutron drip lines. Different Skyrme parametrizations, in particular SkM*, SkX, SkO, SLy4, Skxs25 and Z, have been used in the nonrelativistic region. In the relativistic region, the density-dependence meson-exchange models and density-dependence point-coupling models are used. Both methods are used to study ground state properties such as binding energy, mass radial density distribution and the corresponding root mean square (rms) mass radii. The fragmentation reaction cross-section is used as an important property to investigate the halo structure. Strong evidence for existence of a neutron halo in [Formula: see text]Li and [Formula: see text]Be and proton halo in [Formula: see text]Ne, [Formula: see text]Al and [Formula: see text]P are found using the SHF model and reaction cross-section. The ability of the SHF model to study the exotic structure with shell model occupation probability is confirmed.

EELS white line intensities calculated for the 3d and 4d metals

1989 ◽  
Vol 47 ◽  
pp. 388-389
Author(s):  
C. C. Ahn ◽  
D. H. Pearson ◽  
P. Rez ◽  
B. Fultz
Keyword(s):  
Experimental Data ◽  
Line Intensity ◽  
Transition Probabilities ◽  
Initial Increase ◽  
White Line ◽  
Hartree Fock ◽  
Line Intensities ◽  
Integrated Intensity ◽  
X Ray Absorption ◽  
The Continuum

Previous experimental measurements of the total white line intensities from L2,3 energy loss spectra of 3d transition metals reported a linear dependence of the white line intensity on 3d occupancy. These results are inconsistent, however, with behavior inferred from relativistic one electron Dirac-Fock calculations, which show an initial increase followed by a decrease of total white line intensity across the 3d series. This inconsistency with experimental data is especially puzzling in light of work by Thole, et al., which successfully calculates x-ray absorption spectra of the lanthanide M4,5 white lines by employing a less rigorous Hartree-Fock calculation with relativistic corrections based on the work of Cowan. When restricted to transitions allowed by dipole selection rules, the calculated spectra of the lanthanide M4,5 white lines show a decreasing intensity as a function of Z that was consistent with the available experimental data.Here we report the results of Dirac-Fock calculations of the L2,3 white lines of the 3d and 4d elements, and compare the results to the experimental work of Pearson et al. In a previous study, similar calculations helped to account for the non-statistical behavior of L3/L2 ratios of the 3d metals. We assumed that all metals had a single 4s electron. Because these calculations provide absolute transition probabilities, to compare the calculated white line intensities to the experimental data, we normalized the calculated intensities to the intensity of the continuum above the L3 edges. The continuum intensity was obtained by Hartree-Slater calculations, and the normalization factor for the white line intensities was the integrated intensity in an energy window of fixed width and position above the L3 edge of each element.

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