Dipole-dipole scattering at high energy in the Pomeron field theory with Braun Hamiltonian and beyond

In this paper we find that the scattering matrix for dipole-dipole interaction in the saturation region has the form: ${\cal S}^d_d \xrightarrow{z \,\gg\,1} \exp\Lb - C^d_d z^2\Rb \propto \Lb {\cal S}_{BK}\Rb^4 = \exp\Lb - 4\,C_{BK} z^2\Rb$, where $z = \bas κY\,+\,\ln\Lb \frac{r^2}{r'^2}\Rb$ for int