Differential and total cross sections for antiproton-impact ionization of atomic hydrogen and helium

Semiclassical fully differential ionization cross sections of helium with negatively charged fast projectiles

“…At the same time, the scattering plane results obtained for slower antiproton projectiles show larger shifts of the binary and recoil peaks in comparison with other theories [12]. In the perpendicular plane, for small momentum transfers the magnitude of the semiclassical FDCS is the same as in experiments, and the predicted structure seems to be closer to the experiment than that predicted by other theories.…”

“…In the last years the theoreticians' attention has been directed to negatively charged antiproton projectiles [12]. In order to show the limits of the semiclassical approximation, FDCS for ionization produced by 500 keV antiproton projectiles are calculated and compared with the theoretical data of McGovern et al [12]. The velocity of this projectile is almost half of the previous electron projectile velocity.…”

“…The contribution of this term becomes more significant in case of higher momentum transfers producing more visible shoulders in the semiclassical FDCS data. In the last years the theoreticians' attention has been directed to negatively charged antiproton projectiles [12]. In order to show the limits of the semiclassical approximation, FDCS for ionization produced by 500 keV antiproton projectiles are calculated and compared with the theoretical data of McGovern et al [12].…”

“…In order to test the validity of the results of our semiclassical model for the ionization of helium by negative projectiles, calculated FDCS for fast electron and antiproton projectile impact are compared with available experimental and other theoretical data [7,11,12]. Then, a partial wave analysis for different ejection planes is also performed.…”

“…On the other hand, many theoretical models have been applied to explain FDCS measurements of single ionization of helium by fast C 6+ ion [8][9][10] and electron [11] impact. Moreover, in the last years the theoreticians' attention has been directed to negatively charged antiproton projectiles [12]. Here, the results are mostly compared with first-order Born calculations.…”