Single- and double-ionization processes of antiproton-helium and antiproton–molecular hydrogen collisions in the keV energy range

Abstract

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Ab Initio Double-Differential Ionization Cross-Section Calculations in Antiproton–Helium Collisions

“…Solid green line: cross-sections from [9]. The red triangles are the newest theoretical results from [34]. The blue points are the latest measurements of [3] and the blue triangles and blue squared are the measurements of [2,3], respectively.…”

“…In 2011, Kirchner and Knudsen published a topical review which exhaustively discussed and compared all the experimental results and theoretical model calculations [26]. In recent years, numerous additional studies were published regarding antiproton-helium or antiproton-atom and antiproton-molecule collisions from basically the same groups [27][28][29][30][31][32][33][34].…”

Time-Dependent Density Functional Theory for Atomic Collisions: A Progress Report

“…The first question was studied in [32], in which configuration-interaction calculations for antiproton-helium and antiproton-molecular hydrogen collisions were carried out and I c was calculated from P 0 , P 1 , P 2 using Equation (36). To address the second question, we can begin by rewriting Equation (32) as…”

“…For the case of antiproton impact, a comparison with previous calculations was made in [31]. More recent (non-DFT) state-of-the-art studies of antiproton-helium collisions have been presented in [32,49,50]. [36] with different final-state analyses): blue dotted lines, IEM for proton impact; red dashdotted lines, IEM for antiproton impact; blue dashed lines, WB for proton impact; red solid lines, WB for antiproton impact.…”

“…Equation ( 27)) remains unsolved; the cubic and quartic models merely replace the IEM relation by a different one, and given the similarity of cross-section results displayed in Figure 6, it must be concluded that the WB model does not offer more flexibility in practice. The two-electron calculations reported in Reference [32] indicate that such flexibility is needed in reality. In particular, it has been shown there that the correlation integral tends to be positive at relatively high impact energies, a feature that is clearly beyond the capabilities of the models discussed in this section.…”