Summing large Pomeron loops in the saturation region: dipole-nucleus collision beyond nonlinear equations

TL;DR

This paper derives the dipole-nucleus scattering amplitude at high energies by summing large Pomeron loops, revealing that the energy dependence matches dipole-dipole scattering and questioning the universal applicability of the BK equation.

Contribution

It provides a new method to sum large Pomeron loops in the saturation region, extending understanding of high-energy dipole-nucleus interactions beyond nonlinear equations.

Findings

The energy dependence of the amplitude matches dipole-dipole scattering.

The BK equation's validity is limited to certain energy ranges.

Summation of Pomeron loops modifies the expected energy behavior.

Abstract

In this paper we found the dipole-nucleus scattering amplitude at high energies by summing large Pomeron loops. It turns out that the energy dependence of this amplitude is the same as for dipole-dipole scattering. It means that the Balitsky-Kovchegov (BK) equation, which has been derived to describe this scattering, can be trusted only in the limited range of energies: $z \,\leq\, \sqrt{2\,\kappa\,C}A^{1/6} $