Coulomb form factors of 25Mg nuclei using Bohr–Mottelson collective model with Skyrme interaction potential

2020 ◽  
Vol 29 (07) ◽  
pp. 2050048
Author(s):  
Ibtihaj Abdul Hassan Ajeel ◽  
Mohammed J. R. Aldhuhaibat ◽  
Khalid S. Jassim
Keyword(s):  
Electron Scattering ◽  
Interaction Potential ◽  
Form Factors ◽  
Collective Model ◽  
Wave Functions ◽  
Matrix Elements ◽  
Skyrme Interaction ◽  
Core Polarization ◽  
Model Calculations ◽  
Good Agreement

Coulomb [Formula: see text] and C4 form factors to the 5/2[Formula: see text], 7/2[Formula: see text], 9/2[Formula: see text], 9/2[Formula: see text] and 11/2[Formula: see text] states in [Formula: see text]Mg nuclei have been studied using shell model calculations. The universal sd-shell interaction A (USDA) is used for sd-shell orbits. Two models have been used to calculate core-polarization (CP) effects. These models are Coulomb Valance Tassie model (CVTM) and Bohr–Mottelson (BM) collective model. The wave functions of radial single particle matrix elements have been calculated with Skyrme interaction potential (SKX). Electron scattering factors results showed good agreement using the BM collective model comparing with the experimental data.

Inelastic electric and magnetic electron scattering form factors of 24Mg nucleus: Role of g factors

2017 ◽  
Vol 26 (05) ◽  
pp. 1750032 ◽  
Author(s):  
Anwer A. Al-Sammarraie ◽  
M. L. Inche Ibrahim ◽  
Muna Ahmed Saeed ◽  
Fadhil I. Sharrad ◽  
Hasan Abu Kassim
Keyword(s):  
Experimental Data ◽  
Electron Scattering ◽  
Form Factors ◽  
Wave Functions ◽  
Matrix Elements ◽  
Model Hamiltonian ◽  
Transverse Electron ◽  
Magnetic Electron ◽  
Good Agreement

The electric and magnetic transitions in the [Formula: see text]Mg nucleus are studied based on the calculations of the longitudinal and the transverse electron scattering form factors. The universal sd-shell model Hamiltonian (USDA) is used for calculations. The wave functions of radial single-particle matrix elements are calculated using the Skyrme potential. For the longitudinal form factors, a good agreement is obtained between the calculations and the experimental data. For the transverse form factors, the effective [Formula: see text] factors are made as adjustable parameters in order to describe the experimental data.

scholarly journals Investigation of density and form factor of some F isotopes using Hartree-Fock and shell model calculations

2019 ◽  
Vol 14 (30) ◽  
pp. 158-171
Author(s):  
Wasan Z. Majeed
Keyword(s):  
Shell Model ◽  
Electron Scattering ◽  
Form Factors ◽  
Skin Thickness ◽  
Neutron Skin ◽  
Model Calculations ◽  
Hartree Fock ◽  
Density Distributions ◽  
Tail Part ◽  
Good Agreement

Structure of unstable 21,23,25,26F nuclei have been investigatedusing Hartree – Fock (HF) and shell model calculations. The groundstate proton, neutron and matter density distributions, root meansquare (rms) radii and neutron skin thickness of these isotopes arestudied. Shell model calculations are performed using SDBAinteraction. In HF method the selected effective nuclear interactions,namely the Skyrme parameterizations SLy4, Skeσ, SkBsk9 andSkxs25 are used. Also, the elastic electron scattering form factors ofthese isotopes are studied. The calculated form factors in HFcalculations show many diffraction minima in contrary to shellmodel, which predicts less diffraction minima. The long tailbehaviour in nuclear density is noticeable seen in HF more than shellmodel calculations. The deviation occurs between shell model andHF results are attributed to the sensitivity of charge form factors tothe change of the tail part of the charge density. Calculations donefor the rms radii in shell model showed excellent agreement withexperimental values, while HF results showed an overestimation inthe calculated rms radii for 21,23F and good agreement for 25,26F. Ingeneral, it is found that the shell model and HF results have the samebehaviour when the mass number (A) increase.

Microscopic Large Scale psd Shell Model with M3Y Residual Interaction to Calculate Electron Scattering Form Factors

2017 ◽  
Vol 6 (1) ◽  
pp. 56-61
Author(s):  
Khalid S. Jassim ◽  
Rawaa A. Abdul-Nabe
Keyword(s):  
Shell Model ◽  
Electron Scattering ◽  
Large Scale ◽  
Theoretical Calculations ◽  
Form Factors ◽  
Scale Model ◽  
Core Polarization ◽  
Model Calculations ◽  
Polarization Effects ◽  
Realistic Interaction

The longitudinal and the transverse electron scattering form factors for 6Li, 9Be, 11B and 12C nuclei have been studied with and without core polarization effects using shell model calculations. The psdmwk is used as effective interaction for psd-shells. The core-polarization effects are calculated in the first-order perturbation theory including excitations up to 4ħω using the Michigan three-range Yakawa M3Y as a realistic interaction. The wave functions of radial single particle matrix elements have been calculated with harmonic oscillator potential. For all nuclei under studying, Comparison between experimental and theoretical calculations show that the form factors with core-polarization effect calculations give good consistency with experiment data. So we concluded that the large scale model space enhanced the results to become closed to the experimental data.

Longitudinal electron scattering form factors for 54,56Fe

2014 ◽  
Vol 23 (10) ◽  
pp. 1450054 ◽  
Author(s):  
A. D. Salman ◽  
D. R. Kadhim
Keyword(s):  
Electron Scattering ◽  
Effective Charge ◽  
Effective Interaction ◽  
Form Factors ◽  
Nucleon Nucleon ◽  
Model Calculations ◽  
The Core ◽  
Realistic Interaction ◽  
Modified Surface ◽  
Good Agreement

In this paper, inelastic longitudinal electron scattering form factors for C2 transition have been studied in 54 Fe and 56 Fe with the aid of shell model calculations. The GX1 effective interaction for the fp-shell is used with the nucleon–nucleon realistic interaction Michigan three-range Yukawa and Modified surface delta interaction as a two-body interactions. The core polarization effects is taken into account through the first-order perturbation theory with the effective charge, which is taken to the proton and the neutron. The effective charge along with the core effects up to 6 ℏw enhanced the calculation very well and improving good agreement with the experimental data.

Isovector excitation of stretched states in nuclei: effects of meson exchange currents, unbound wave functions, and knockout exchange amplitudes on the extraction of particle–hole strengths

1987 ◽  
Vol 65 (6) ◽  
pp. 666-676 ◽  
Author(s):  
R. A. Lindgren ◽  
M. Leuschner ◽  
B. L. Clausen ◽  
R. J. Peterson ◽  
M. A. Plum ◽  
...  
Keyword(s):  
Electron Scattering ◽  
Transition Amplitude ◽  
Form Factors ◽  
Wave Functions ◽  
Meson Exchange ◽  
Valence Nucleon ◽  
Radial Wave ◽  
Model Calculations ◽  
Nucleus Scattering ◽  
Meson Exchange Currents

It is well known that the strength for excitations of [Formula: see text] high spin, stretched states observed via inelastic scattering, is generally much smaller than that predicted by spherical shell-model calculations. In addition, results obtained from electromagnetic and hadronic studies have discrepancies at the 20% level. For us to gain a better understanding of reduced magnetic strength in electron scattering and hopefully close the gap between experiment and theory, calculations of the electron-scattering form factors have been performed including the effects due to meson exchange currents in the transition amplitude and the effects due to unbound wave functions for the valence nucleon. The effect of the meson exchange-current contributions is to uniformly enhance the form factors near the first maximum, resulting in a 16 to 20% further reduction of the stretched particle–hole strength. The effect due to the radial wave functions deduced from Woods–Saxon potentials in which the nucleon is not bound is to reduce the form factors, thereby resulting in an increase in the spectroscopic strength. As regards the comparison of results obtained with electromagnetic and hadronic probes, the implied sensitivity to higher order current and spin–current transition densities associated with the nonlocality due to the tensor knockout exchange amplitudes in nucleon–nucleus scattering is considered explicitly. It is found that the simplest correspondence between electron and nucleon–nucleus scattering is preserved for isovector excitations but not for isoscalar excitations under the usual assumptions for the tensor interaction. It is clear that precise comparisons between experiment and theory (or between probes) cannot be made unless these and related effects are consistently included.

scholarly journals Large Scale Shell Model Calculations of the Negative-Parity States Structure in 24Mg Nucleus

2021 ◽  
Vol 66 (4) ◽  
pp. 293
Author(s):  
A.A. Al-Sammarraie ◽  
F.A. Ahmed ◽  
A.A. Okhunov
Keyword(s):  
Shell Model ◽  
Large Scale ◽  
Transition Probabilities ◽  
Transition Probability ◽  
Energy Levels ◽  
Form Factors ◽  
Model Space ◽  
Negative Parity ◽  
Matrix Elements ◽  
Model Calculations

The negative-parity states of 24Mg nucleus are investigated within the shell model. We are based on the calculations of energy levels, total squared form factors, and transition probability using the p-sd-pf (PSDPF) Hamiltonian in a large model space (0 + 1) hW. The comparison between the experimental and theoretical states showed a good agreement within a truncated model space. The PSDPF-based calculations successfully reproduced the data on the total squared form factors and transition probabilities of the negative-parity states in 24Mg nucleus. These quantities depend on the one-body density matrix elements that are obtained from the PSDPF Hamiltonian. The wave functions of radial one-particle matrix elements calculated with the harmonic-oscillator potential are suitable to predict experimental data by changing the center-of-mass corrections.

scholarly journals The Nuclear Structure for Exotic Neutron-Rich of 42, 43, 45,47K Nuclei

2016 ◽  
Vol 13 (1) ◽  
pp. 146-154
Author(s):  
Baghdad Science Journal
Keyword(s):  
Magnetic Dipole ◽  
Electron Scattering ◽  
Dipole Moments ◽  
Exotic Nucleus ◽  
Form Factors ◽  
Model Space ◽  
Density Distributions ◽  
Plane Wave Born Approximation ◽  
Magnetic Electron ◽  
Good Agreement

In this paper the proton, neutron and matter density distributions and the corresponding root mean square (rms) radii of the ground states and the elastic magnetic electron scattering form factors and the magnetic dipole moments have been calculated for exotic nucleus of potassium isotopes K (A= 42, 43, 45, 47) based on the shell model using effective W0 interaction. The single-particle wave functions of harmonic-oscillator (HO) potential are used with the oscillator parameters b. According to this interaction, the valence nucleons are asummed to move in the d3f7 model space. The elastic magnetic electron scattering of the exotic nuclei 42K (J?T= 2- 2), 43K(J?T=3/2+ 5/2), 45K (J?T= 3/2+ 7/2) and 47K (J?T= 1/2+ 9/2) investigated through Plane Wave Born Approximation (PWBA). The inclusion of core polarization effect through the effective g-factors is adequate to obtain a good agreement between the predicted and the measured magnetic dipole moments.

scholarly journals O2 State in 18 O by using Core – Polarization effects

2008 ◽  
pp. 66-72
Keyword(s):  
Perturbation Theory ◽  
Experimental Studies ◽  
Form Factors ◽  
Wave Model ◽  
Collective Model ◽  
Core Polarization ◽  
Polarization Effects ◽  
The Core ◽  
The Subject ◽  
Space Wave

Coulomb form factors for E0 transition in 18O are discussed taking into account core-polarization effects. These effects are taken into account through the collective model of Tassie and also through a microscopic perturbation theory including excitations up to 2p1f shell. Space wave model functions defined for the orbits 1 and 2125O nucleus has been the subject of extensive theoretical and experimental studies, which received much attention in last decade [Alex Brown et.al.2005]. The 18O system contains two neutrons in addition to the16O core distributed in the sd – shell. d1 are obtained from the diagonalization of the interaction Hamilonian of Wildenthal. The calculations include the 0 2state with excitation energies3.6337MeV. The core – polarization effects which incorporate the ollective model of Tassei describe the data very well for this state.

55 YEARS OF THE SHELL MODEL: A CHALLENGE TO NUCLEAR MANY-BODY THEORY

2005 ◽  
Vol 14 (06) ◽  
pp. 821-844 ◽  
Author(s):  
IGAL TALMI
Keyword(s):  
Shell Model ◽  
Wave Functions ◽  
Many Body ◽  
Apparent Absence ◽  
Model Calculations ◽  
Many Body Theory ◽  
Body Theory ◽  
Nuclear Many Body Theory ◽  
Closed Shells ◽  
Good Agreement

Shell model calculations of nuclear energies and wave functions of nucleons outside closed shells interacting by effective two-body forces yield good agreement with much experimental data. Many attempts have been made to calculate nuclear energies ab initio, by starting from some form of an interaction between free nucleons. Recent results of such calculations claim to obtain reasonable agreement with measured energies. These results, however, are obtained for wave functions which are very complicated. It is difficult to see how such wave functions are consistent with independent nucleon motion, the very essence of the shell model. In some of those calculations, 3-body interactions play a very important role. This is puzzling since nuclear energies are accurately obtained in shell model calculations by using only effective two-body interactions. In this paper, some examples of simple shell model calculations are reviewed. They exhibit good agreement with experiment and the apparent absence of the need for effective 3-body interactions.

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