Pseudostate methods and differential cross sections for antiproton ionization of atomic hydrogen and helium

Journal Article · Mon Mar 15 00:00:00 EDT 2010 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.81.032708· OSTI ID:21408433

McGovern, M; Walters, H R. J. ^[1]; Assafrao, D; Mohallem, J R ^[2]; Whelan, Colm T ^[3]

---

1. Department of Applied Mathematics and Theoretical Physics, Queen's University, Belfast BT7 1NN (United Kingdom)
2. Laboratorio de Atomos e Moleculas Especiais, Departamento de Fisica, ICEx, Universidade Federal de Minas Gerais, P. O. Box 702, 30123-970 Belo Horizonte, MG (Brazil)
3. Department of Physics, Old Dominion University, Norfolk, Virginia 23529-0116 (United States)

A relaxed form of a recent impact parameter coupled pseudostate approximation of McGovern et al. [Phys. Rev. A 79, 042707 (2009)] for calculating differential ionization cross sections is proposed. This greatly eases the computational burden in cases where a range of ejected electron energies has to be considered. The relaxed approximation is tested against exact first Born calculations for antiproton impact on H and nonperturbatively for the highly nonperturbative system of Au{sup 53+} incident upon He. The approximation performs well in these tests. It is shown how, with a little further approximation, the relaxed theory leads to a widely used prescription for the total ionization cross section. Results for differential ionization of H and He by antiprotons are presented. These reveal the growing dominance of the interaction between the antiproton and the target nucleus at low impact energies and show the changing importance of the role of the postcollisional interaction between the antiproton and the ejected electron.

• OSTI ID: 21408433
• Journal Information: Physical Review. A, Vol. 81, Issue 3; Other Information: DOI: 10.1103/PhysRevA.81.032708; (c) 2010 The American Physical Society; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ANTIPROTONS
APPROXIMATIONS
DIFFERENTIAL CROSS SECTIONS
ELECTRONS
HELIUM
HYDROGEN
IMPACT PARAMETER
INTERACTIONS
IONIZATION
ANTIBARYONS
ANTIMATTER
ANTINUCLEI
ANTINUCLEONS
ANTIPARTICLES
BARYONS
CALCULATION METHODS
CROSS SECTIONS
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
FLUIDS
GASES
HADRONS
LEPTONS
MATTER
NONMETALS
NUCLEI
NUCLEONS
PROTONS
RARE GASES