Collisions of antiprotons with hydrogen molecular ions

TL;DR

This study presents detailed calculations of ionization and excitation cross sections for antiprotons colliding with hydrogen molecular ions across a wide energy range, using advanced quantum mechanical approximations.

Contribution

It introduces an efficient method using three molecular orientations to accurately compute ionization cross sections, reducing computational effort significantly.

Findings

Accurate ionization cross sections obtained with minimal orientations.

Validation against previous results shows high agreement.

Approximate double ionization and H+ production cross sections using the independent-event model.

Abstract

Time-dependent close-coupling calculations of the ionization and excitation cross section for antiproton collisions with molecular hydrogen ions are performed in an impact-energy range from 0.5 keV to 10 MeV. The Born-Oppenheimer and Franck-Condon approximations as well as the impact parameter method are applied in order to describe the target molecule and the collision process. It is shown that three perpendicular orientations of the molecular axis with respect to the trajectory are sufficient to accurately reproduce the ionization cross section calculated by [Sakimoto, Phys. Rev. A 71, 062704 (2005)] reducing the numerical effort drastically. The independent-event model is employed to approximate the cross section for double ionization and H+ production in antiproton collisions with H2.