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.

Effects of the isoscalar and isovector interaction on the ground-state magnetic moments of odd-mass 137–145Ce nuclei

2019 ◽  
Vol 97 (11) ◽  
pp. 1187-1190
Author(s):  
H. Yakut ◽  
E. Tabar ◽  
G. Hoşgör
Keyword(s):  
Ground State ◽  
Magnetic Moments ◽  
The Other ◽  
Spin Interaction ◽  
Nuclear Model ◽  
Isotopic Chain ◽  
Core Polarization ◽  
Polarization Effects ◽  
The Core

A systematic study of the magnetic properties of deformed odd-neutron 137–145Ce isotopes using the microscopic quasiparticle phonon nuclear model (QPNM) has been presented. The QPNM includes residual spin–spin interaction in both isoscalar and isovector channels. The analysis shows that in the isoscalar channel contributions to the magnetic moment coming from the neutron and proton systems practically cancel out each other. On the other hand, in the isovector channel, the coherent contribution coming from the quasiparticle–phonon interactions leads to a spin polarization (core polarization), which is important for determination of the quenched spin gyromagnetic factors (gs). The quenched spin gyromagnetic factors so called [Formula: see text] have been found to range from [Formula: see text] to [Formula: see text] in the odd-mass 137–145Ce isotopic chain, which is similar to its phenomenological value ([Formula: see text] between [Formula: see text] and [Formula: see text]). By taking into consideration the core polarization effects, the available experimental data are satisfactorily reproduced with an accuracy of 0.01μN–0.1μN.

Core-polarization effects on C2 form factors of p-shell nuclei

2001 ◽  
Vol 696 (3-4) ◽  
pp. 442-452 ◽  
Author(s):  
R.A. Radhi ◽  
A.A. Abdullah ◽  
Z.A. Dakhil ◽  
N.M. Adeeb
Keyword(s):  
Form Factors ◽  
Core Polarization ◽  
Polarization Effects

scholarly journals Inelastic electron scattering form factors involving the second excited 2+ level in the isotopes 50,54,52Cr

2019 ◽  
Vol 13 (28) ◽  
pp. 19-26
Author(s):  
Ghaith Naima Flaiyh
Keyword(s):  
Charge Density ◽  
Form Factors ◽  
Transition Density ◽  
Collective Modes ◽  
Inelastic Electron ◽  
Core Polarization ◽  
Density Distributions ◽  
The Core ◽  
Model Transition ◽  
Remarkable Agreement

An expression for the transition charge density is investigated where the deformation in nuclear collective modes is taken into consideration besides the shell model transition density. The inelastic longitudinal form factors C2 calculated using this transition charge density with excitation of the levels for Cr54,52,50 nuclei. In this work, the core polarization transition density is evaluated by adopting the shape of Tassie model together with the derived form of the ground state two-body charge density distributions (2BCDD's). It is noticed that the core polarization effects which represent the collective modes are essential in obtaining a remarkable agreement between the calculated inelastic longitudinal F(q)'s and those of experimental data.

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.

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.

scholarly journals Microscopic calculations of the electric Quadrupole transition strengths of Be isotopes (9, 10, 12, 14)

2019 ◽  
Vol 12 (24) ◽  
pp. 87-99
Author(s):  
Sara. H. Ibrahim
Keyword(s):  
Harmonic Oscillator ◽  
Shell Model ◽  
Electric Quadrupole ◽  
Transition Strength ◽  
Matrix Elements ◽  
Core Polarization ◽  
Model Calculations ◽  
Polarization Effects ◽  
The Core ◽  
Effective Charges

Electric Quadrupole transitions are calculated for beryllium isotopes (9, 10, 12 and 14). Calculations with configuration mixing shell model usually under estimate the measured E2 transition strength. Although the consideration of a large basis no core shell model with 2ℏtruncations for 9,10,12 and14 where all major shells s, p, sd are used, fail to describe the measured reduced transition strength without normalizing the matrix elements with effective charges to compensate for the discarded space. Instead of using constant effective charges, excitations out of major shell space are taken into account through a microscopic theory which allows particle–hole excitations from the core and model space orbits to all higher orbits with 2ℏw excitations which are called core-polarization effects. The two body Michigan sum of three ranges Yukawa potential (M3Y) is used for the core-polarization matrix element. The simple harmonic oscillator potential is used to generate the single particle matrix elements of all isotopes considered in this work. The b value of each isotope is adjusted to reproduce the experimental matter radius, These size parameters of the harmonic oscillator almost reproduce all the root mean square (rms) matter radii for 9,10,12,14Be isotopes within the experimental errors. Almost same effective charges are obtained for the neutron- rich Be isotopes which are smaller than the standard values. The major contribution to the transition strength comes from the core polarization effects. The present calculations of the neutron-rich 12,14Beisotopes show a deviation from the general trends in accordance with experimental and other theoretical studies. The configurations arises from the shell model calculations with core-polarization effects reproduce the experimental B(E2) values.

CORE NUCLEUS DYNAMICS IN Λ HYPERNUCLEI

2009 ◽  
Vol 18 (05n06) ◽  
pp. 1302-1312
Author(s):  
Q. N. USMANI ◽  
A. R. BODMER ◽  
ZALIMAN SAULI
Keyword(s):  
Nuclear Matter ◽  
Compression Modulus ◽  
Fermi Theory ◽  
Core Nucleus ◽  
Core Polarization ◽  
Polarization Effects ◽  
Thomas Fermi ◽  
The Core

We develop a Thomas Fermi theory to study the core polarization effects in Λ hypernuclei. Nuclei in the range of 10B to 243Am are included. Core polarization energies and changes in rms radii due to presence of Λ are calculated. It is shown that core polarization effects depend crucially on the effective compression modulus of the nucleus rather than on the compression modulus of the corresponding infinite nuclear matter.

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