DWBA theory for elastic scattering of polarized electrons from heavy unpolarized nuclei

Abstract

Differential cross sections and spin asymmetries for the elastic scattering of spin-polarized electrons from inert spin- nuclei are calculated within the distorted-wave (DW) Born approximation. This is achieved by means of a coherent superposition of the electric and magnetic (M1) transition amplitudes, using Dirac eigenfunctions for the electronic scattering states throughout. For heavy nuclei (Z ≳ 40), high collision energies and backward scattering angles considerable deviations occur from previous DW plane-wave calculations where the magnetic transition is calculated within the Born approximation. For electrons spin-polarized perpendicular to the beam direction the spin asymmetry is quenched when magnetic scattering becomes dominant. Predictions are made for 50–200 MeV electrons scattering from 15N, 89Y and 207Pb nuclei.

Theoretical study on nuclear structure by the multiple Coulomb scattering and magnetic scattering of relativistic electrons

“…The Coulomb distortion corrections are very significant during the theoretical studies of electron scattering [41]. Under the theoretical framework of Eq.…”

“…This calculation method is also referred to as the distorted-wave Born approximation (DWBA) [40,41]. The phase-shift analysis method is an accurate method to calculate the cross sections of scattering electrons and has been applied in many theoretical studies [32,33,34,35,36,37,38].…”

“…The phase-shift analysis method is an effect way to study the electron scattering which includes the Coulomb distortion effects by the exact phase-shift analysis of Dirac equations. This calculation method is also referred to as the distorted-wave Born approximation (DWBA) [40,41]. The phase-shift analysis method is an accurate method to calculate the cross sections of scattering electrons and has been applied in many theoretical studies [32,33,34,35,36,37,38].…”

Extraction of the second and fourth radial moments of nuclear charge density from the elastic electron-nucleus scattering

“…The results show that in the region of the small momentum transfer q, the r 2 c and r 4 [3,4], where the |F C (q)| 2 are expressed as the Fourier transformation of the density distributions. However, because the Coulomb distortion effects are neglected, the PWBA method calculations are not accurate enough, especially for the heavy nuclei [31,32]. In order to calculate the |F C (q)| 2 more adequately, the eikonal approximation [33] and phase shift analysis method [34,35,36] termed as the distorted wave Born approximation (DWBA) [31] method are introduced by including the Coulomb distortion effects.…”

“…However, because the Coulomb distortion effects are neglected, the PWBA method calculations are not accurate enough, especially for the heavy nuclei [31,32]. In order to calculate the |F C (q)| 2 more adequately, the eikonal approximation [33] and phase shift analysis method [34,35,36] termed as the distorted wave Born approximation (DWBA) [31] method are introduced by including the Coulomb distortion effects. Compared with the PWBA method, the |F C (q)| 2 calculated by the DWBA method coincides better with the experimental data [23,31].…”