Atomic ionization by multicharged ions interpreted in terms of poles in the charge complex space

TL;DR

This paper investigates atomic ionization caused by multicharged ions using Padé approximants to interpret cross sections, revealing poles in the charge complex plane that correlate with oscillations in ionization cross sections.

Contribution

It introduces a novel interpretation of ionization cross sections through poles in the charge complex space using Padé approximants, linking theoretical and experimental results.

Findings

Poles in the charge complex plane move with projectile velocity.

Ionization cross sections exhibit oscillations related to incident charge.

Theoretical and experimental pole positions show consistent patterns.

Abstract

In this work we study the single ionization of hydrogen and helium by the impact of a punctual Coulomb projectile. To interpretate the cross section we introduce a series of Pad\'{e} approximant. The nodes of the denominator of the Pad\'{e} approximant give rise to poles in the charge complex plane. These poles move with the projectile velocity following a certain pattern. We find the positions of the poles of the Continuum Distorted Wave theory and an ensamble of experimental results. It was found that the ionization cross section may have oscillations in terms of the incident charge for a given impact velocity.