Differential ionization in antiproton–hydrogen collisions within the convergent-close-coupling approach

Abstract

A recently developed fully quantal convergent-close-coupling (CCC) approach (Abdurakhmanov et al 2011 J. Phys. B: At. Mol. Opt. Phys. 44 075204) to ion-atom collisions is extended to differential ionization studies. An important feature of the method is that it does not have classical limitations on the relative motion of participating particles. The approach is applied to calculate fully differential, as well as various doubly and singly differential cross sections of ionization in antiproton collisions with atomic hydrogen. The CCC results for various differential cross sections agree reasonably well with the results of the semiclassical CC and the continuum-distorted-wave-eikonal-initial-state approaches, particularly at high energies. However, some discrepancies exist at low energies, where the final state interactions among colliding particles are found to be very important.

Relativistic calculations of differential ionization cross sections: Application to antiproton-hydrogen collisions

“…Following Abdurakhmanov et al [21] and Ciappina et al [22], we adopt their conventions. So the direction of the scattered projectile is fixed by the value of the momentum transfer q or by the projectile deviation angle θ P .…”

“…[16][17][18]. Recently these FDCS have also been studied by several nonperturbative methods [19][20][21][22][23]. Firstly, McGovern et al [19,20] developed a method for extracting the FDCS from an impact-parameter treatment of the collision within a coupled pseudostate (CP) formalism.…”

Classical-trajectory Monte Carlo model calculations for the antiproton-induced ionization of atomic hydrogen at low impact energy

“…In Fig. 3 the quantum mechanical models used in the comparison are the TDCC theory of Ciappina et al [8], the CCC approach of Abdurakhmanov et al [7], and the CDW-EIS model of Voitkiv and Ullrich [9]. The FDCS data of the latter model were taken from Ref.…”

“…However, CDW-EIS is a perturbation theory, its use is justified at high impact energy. solid line, CCC [7]; dashed line, CP [12].…”

“…In this way their model gives account of the NN interaction. The fully quantal, time-independent convergent close-coupling (CCC) model of Abdurakhmanov et al [7] has been developed along the lines of the CCC approach to electron-atom scattering. The model is also based on use of pseudostates, and as a fully quantal theory, it implicitly considers the NN interaction.…”