A collinear model for small-x physics

TL;DR

This paper introduces a simplified collinear model for small-x physics that reduces the complex small-x equation to a second order differential equation, enabling analytical and numerical analysis of perturbative and strong-coupling regimes.

Contribution

It presents a novel collinear model focusing on the enhanced parts of kernels, simplifying the small-x equation to a second order differential form for better analysis.

Findings

The model captures the transition between perturbative and strong-coupling regimes.

Analytical and numerical investigations reveal the behavior of the small-x equation.

The approach clarifies the transition mechanism in two-scale processes.

Abstract

We propose a simple model for studying small-x physics in which we take only the collinearly enhanced part of leading and subleading kernels, for all possible transverse momentum orderings. The small-x equation reduces to a second order differential equation in t=log k^2/Lambda^2 space, whose perturbative and strong-coupling features are investigated both analytically and numerically. For two-scale processes, we clarify the transition mechanism between the perturbative, non Regge regime and the strong-coupling Pomeron behavior.