AdS black disk model for small-x DIS

TL;DR

This paper introduces an AdS black disk model based on approximate conformal invariance of QCD to describe saturation phenomena in deep inelastic scattering at small-x, predicting universal scaling laws and ratios.

Contribution

It proposes a novel AdS black disk framework for small-x DIS saturation, deriving universal power-law scaling and cross section ratios independent of target details.

Findings

Structure functions scale as 1/x^w with energy

Universal ratio of F_L to F_T given by (1+w)/(3+w)

Explicit expressions for photon-photon scattering cross sections

Abstract

Using the approximate conformal invariance of QCD at high energies we consider a simple AdS black disk model to describe saturation in DIS. Deep inside saturation the structure functions have the same power law scaling, F_T ~ F_L ~ 1/x^w, where w is related to the expansion rate of the black disk with energy. Furthermore, the ratio F_L /F_T is given by the universal value (1+w)/(3+w), independently of the target. For virtual photon-photon scattering at high energies we obtain explicit expressions and ratios for the total cross sections of transverse and longitudinal photons in terms of the single parameter w.