Снова об эйконале. Надо бы прочитать...
Bethe's Ansatz for Coulomb -Nuclear Interference Is Incompatible with Additive Eikonal: https://arxiv.org/abs/1906.03895
This is a proof that if the eikonal is additive in strong and electro-magnetic interactions then the application of the Bethe Ansatz for the full scattering amplitude leads to the strong interaction scattering amplitude with the ratio ( real/imaginary) independent on the transferred momentum . Below the
inelastic threshold the strong interaction amplitude is \sim\delta(t).
This is a proof that if the eikonal is additive in strong and electro-magnetic interactions then the application of the Bethe Ansatz for the full scattering amplitude leads to the strong interaction scattering amplitude with the ratio ( real/imaginary) independent on the transferred momentum . Below the
inelastic threshold the strong interaction amplitude is \sim\delta(t).