The Single Differential Cross Sections (SDCS) for H(3s) Ionization in the First-Born Approximation by Electron and Positron Impact

Fuente: arXiv
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Main Authors: Islam, Fahadul, Dhar, Sunil
Format: Preprint
Published: 2025
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author Islam, Fahadul
Dhar, Sunil
author_facet Islam, Fahadul
Dhar, Sunil
contents A theoretical study was conducted on the impact of electron and positron impact ionization of excited hydrogen atoms that were in the 3s state; this study was conducted within the First-Born Approximation (FBA), which provides an analytical expression for the transition matrix in terms of the Bethe-Lewis Integral Formalism. This formalism utilized both Coulomb continuum and confluent hypergeometric functions to describe the scattering states involved. Single Differential Cross Sections (SDCS) were calculated for incident energies of 100, 150, 200, and 250 eV. The data obtained indicated a peak in the ionization rates approximately at 200 eV, with the ionization rate decreasing as the incident energy increased further. The diffuse radial nature of the 3s wave function is shown to increase the sensitivity of the ionization dynamics to the incident particle energy. Asymmetries in charge were also detected; specifically, at low energy of the ejected electron, the SDCS values for positrons were greater than the corresponding values for electrons; however, as the energy of the incident particles was increased, these differences disappeared, thereby demonstrating the applicability of the FBA at high energy limits. The residual differences at low energy were due to the omission of exchange and post-collision interactions from the model. The results of this work can be used as benchmarking for the development of more complex distorted wave and multi-scattering theories in excited state ionization processes.
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id arxiv_https___arxiv_org_abs_2512_04870
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle The Single Differential Cross Sections (SDCS) for H(3s) Ionization in the First-Born Approximation by Electron and Positron Impact
Islam, Fahadul
Dhar, Sunil
Atomic Physics
A theoretical study was conducted on the impact of electron and positron impact ionization of excited hydrogen atoms that were in the 3s state; this study was conducted within the First-Born Approximation (FBA), which provides an analytical expression for the transition matrix in terms of the Bethe-Lewis Integral Formalism. This formalism utilized both Coulomb continuum and confluent hypergeometric functions to describe the scattering states involved. Single Differential Cross Sections (SDCS) were calculated for incident energies of 100, 150, 200, and 250 eV. The data obtained indicated a peak in the ionization rates approximately at 200 eV, with the ionization rate decreasing as the incident energy increased further. The diffuse radial nature of the 3s wave function is shown to increase the sensitivity of the ionization dynamics to the incident particle energy. Asymmetries in charge were also detected; specifically, at low energy of the ejected electron, the SDCS values for positrons were greater than the corresponding values for electrons; however, as the energy of the incident particles was increased, these differences disappeared, thereby demonstrating the applicability of the FBA at high energy limits. The residual differences at low energy were due to the omission of exchange and post-collision interactions from the model. The results of this work can be used as benchmarking for the development of more complex distorted wave and multi-scattering theories in excited state ionization processes.
title The Single Differential Cross Sections (SDCS) for H(3s) Ionization in the First-Born Approximation by Electron and Positron Impact
topic Atomic Physics
url https://arxiv.org/abs/2512.04870