Testing Non-linear Evolution with Running Coupling Corrections in $ep$ and $pp$ collisions

TL;DR

This paper investigates the impact of running coupling corrections on the non-linear evolution equations in high-energy QCD, demonstrating that the improved BK equation accurately describes saturation phenomena in ep and pp collisions.

Contribution

It introduces and tests a running coupling BK solution, showing its effectiveness in describing saturation physics in various high-energy scattering processes.

Findings

Running coupling BK solution fits ep scattering data well.

The model describes forward hadron production in pp collisions.

Saturation effects are confirmed in diffractive deep inelastic scattering.

Abstract

The perturbative QCD predicts that the growth of the gluon density at small-$x$ (high energies) should saturate, forming a Color Glass Condensate (CGC), which is described in mean field approximation by the Balitsky-Kovchegov (BK) equation. Recently, the next-to-leading order corrections for the BK equation were derived and a global fit of the inclusive $ep$ HERA data was performed, resulting in a parameterization for the forward scattering amplitude. In this paper we compare this parameterization with the predictions of other phenomenological models and investigate the saturation physics in diffractive deep inelastic electron-proton scattering and in the forward hadron production in $pp$ collisions. Our results demonstrate that the running coupling BK solution is able to describe these observables.