On the Coulomb corrections to the total cross section of the interaction of the $π^+π^-$ atom with ordinary atoms at high energy

Abstract

The size of $π^+π^-$ atom in the low lying states is considerably smaller than the radius of atomic screening. Due to that we can neglect this screening calculating the contribution of multi-photon exchanges. We obtain the analytic formula for Coulomb corrections which works with a very good accuracy for the ground state of $π^+π^-$ atom.