Anti-hydrogen - Meta-stable helium elastic scattering at thermal energies

This article analyses the results for ground state anti-hydrogen scattering off meta-stable helium (He(21/3S)) targets at thermal energies using atomic orbital expansion technique. The variation of phase shifts indicates that the effective leptonic potential for each system has neither any barrier nor any hump. The zero energy cross sections for both the targets are much greater than the ground state target: σHe(21S)-H¯(1s)=150σHe(11S)-H¯(1s) and σHe(23S)-H¯(1s)=31σHe(11S)-H¯(1s). The maxima of the p-wave cross sections occur in the vicinity of the minima of s-wave result.