NATURAL ORBITALS AND ELECTRON ELASTIC MAGNETIC SCATTERING BY NUCLEI

1996 ◽  
Vol 05 (04) ◽  
pp. 717-724 ◽  
Author(s):  
D.N. KADREV ◽  
A.N. ANTONOV ◽  
M.V. STOITSOV ◽  
S.S. DIMITROVA
Keyword(s):  
Density Fluctuation ◽  
Form Factors ◽  
Wave Functions ◽  
Magnetic Scattering ◽  
Correlation Effects ◽  
Valence Nucleon ◽  
Nucleon System ◽  
Natural Orbitals ◽  
Transverse Form Factor ◽  
Fluctuation Model

Natural orbitals obtained within the coherent density fluctuation model and containing nucleon correlation effects are used to calculate characteristics of the A-nucleon system, such as the electron elastic magnetic scattering form factors. The calculations are performed for nuclei with a doubly-closed core and a valence nucleon in a stretched configuration (j=l+1/2), such as the 17 O and 41 Ca nuclei. It is shown that the calculations of the transverse form factor using natural orbitals improve the agreement with the experimental data in comparison with the case when shell-model single-particle wave functions are used.

Natural orbitals and occupation numbers in the coherent density fluctuation model

1989 ◽  
Vol 102 (6) ◽  
pp. 1701-1715 ◽  
Author(s):  
A. N. Antonov ◽  
E. N. Nikolov ◽  
I. Zh. Petkov ◽  
Chr V. Christov ◽  
P. E. Hodgson
Keyword(s):  
Density Fluctuation ◽  
Natural Orbitals ◽  
Occupation Numbers ◽  
Fluctuation Model

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 Electromagnetic transition form factors of baryons in a relativistic Faddeev approach

2018 ◽  
Vol 181 ◽  
pp. 01013 ◽  
Author(s):  
Reinhard Alkofer ◽  
Christian S. Fischer ◽  
Hèlios Sanchis-Alepuz
Keyword(s):  
Ground State ◽  
Bound States ◽  
Body Wave ◽  
Form Factors ◽  
Wave Functions ◽  
Electromagnetic Form Factors ◽  
Transition Form ◽  
Electromagnetic Transition ◽  
Three Body ◽  
Gluon Interaction

The covariant Faddeev approach which describes baryons as relativistic three-quark bound states and is based on the Dyson-Schwinger and Bethe-Salpeter equations of QCD is briefly reviewed. All elements, including especially the baryons’ three-body-wave-functions, the quark propagators and the dressed quark-photon vertex, are calculated from a well-established approximation for the quark-gluon interaction. Selected previous results of this approach for the spectrum and elastic electromagnetic form factors of ground-state baryons and resonances are reported. The main focus of this talk is a presentation and discussion of results from a recent investigation of the electromagnetic transition form factors between ground-state octet and decuplet baryons as well as the octet-only Σ0 to Λ transition.

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 Meson form-factors and wave-functions with Wilson fermions

1993 ◽  
Vol 30 ◽  
pp. 419-422 ◽  
Author(s):  
Rajan Gupta ◽  
David Daniel ◽  
Jeffrey Grandy
Keyword(s):  
Form Factors ◽  
Wave Functions ◽  
Wilson Fermions

scholarly journals PROBING THE PARTON CONTENT OF THE NUCLEON

2009 ◽  
Vol 24 (35n37) ◽  
pp. 2882-2892 ◽  
Author(s):  
SIGFRIDO BOFFI ◽  
BARBARA PASQUINI
Keyword(s):  
Light Cone ◽  
Cloud Model ◽  
Form Factors ◽  
Wave Functions ◽  
Electromagnetic Form Factors ◽  
Transition Distribution ◽  
Meson Cloud

The parton content of the nucleon is explored within a meson-cloud model developed to derive light-cone wave functions for the physical nucleon. The model is here applied to study electromagnetic form factors, distribution amplitudes and nucleon-to-meson transition distribution amplitudes.

Low-energy pion photoproduction from p-shell nuclei

1990 ◽  
Vol 68 (11) ◽  
pp. 1270-1278 ◽  
Author(s):  
C. Bennhold ◽  
L. Tiator ◽  
L. E. Wright
Keyword(s):  
Form Factors ◽  
Pion Photoproduction ◽  
Binding Energies ◽  
Wave Functions ◽  
Low Energy ◽  
Delta Resonance ◽  
Transverse Electromagnetic ◽  
Coulomb Effects ◽  
Correction Terms ◽  
Space Approach

Low-energy pion photoproduction off 6Li, 10B, and 14N has been reinvestigated in a DWIA framework that includes a number of improvements neglected in previous analyses. The production operator is based on Feynman diagrams and includes correction terms of order p2/M2 and higher. An s-channel delta resonance term is included with both longitudinal and transverse electromagnetic couplings. Rather than using on harmonic oscillator for the nucleon orbitals we employ Woods–Saxon wave functions that have been adjusted to fit electron-scattering form factors and single-particle binding energies. Furthermore, we include the Coulomb potential without approximation in our momentum-space approach. Using more realistic wave functions and including corrections to the production amplitude that have been neglected before leads to considerable improvement in the case of 10B and 14N when compared with existing data. The Coulomb effects are shown to change the cross section by about 30% close to threshold but are negligible at higher energies.

Sign in / Sign up

Export Citation Format

Share Document