Single ionization of He by high-energy proton and antiproton. A QED approach

We have investigated single ionization of He by fast proton and antiproton using a QED approach. A field theoretical calculation gives the total cross -section of He in single ionization, from which it is seen that the project ile p(+) or p(-) gives almost the same values of cross-section. We have als o compared our results with other theoretical and experimental results avai lable in this context yet. Behaviour of the cross-section at a lower spectr um of projectile energy is discussed.