Enhanced backscattering in antiproton-atom collision: Coulomb glory

The head-on collisions of an antiproton with an atom result in backscattering due to the attractive Coulomb p(-)-nucleus interaction. Accounting for the screening of the Coulomb potential by atomic electrons leads to amplification of the backscattering. The effect is manifested at collision energies of about 2 keV, when the extended range of impact parameters contributes to the differential cross section at scattering angles close to 180 degrees. Our calculations for the representative case of p(-)-Xe collision characterize quantitatively the main features of such a Coulomb glory phenomenon.