Non-perturbative QCD effects in forward scattering at LHC

TL;DR

This paper investigates non-perturbative QCD effects in high-energy forward scattering at the LHC by modeling infrared contributions with an effective charge, connecting parton dynamics to hadron scattering, and comparing predictions with recent experimental data.

Contribution

It introduces an eikonal QCD model incorporating an infrared finite effective charge and energy-dependent form factors, providing improved predictions for total cross sections and scattering ratios.

Findings

Predictions align with TOTEM, AUGER, and Telescope Array data.

The model successfully describes the high-energy behavior of forward scattering.

Inclusion of energy-dependent form factors enhances the accuracy of the amplitude predictions.

Abstract

We study infrared contributions to semihard parton-parton interactions by considering an effective charge whose finite infrared behavior is constrained by a dynamical mass scale. Using an eikonal QCD-based model in order to connect this semihard parton-level dynamics to the hadron-hadron scattering, we obtain predictions for the proton-proton ($pp$) and antiproton-proton ($\bar{p}p$) total cross sections, $\sigma_{tot}^{pp,\bar{p}p}$, and the ratios of the real to imaginary part of the forward scattering amplitude, $\rho^{pp,\bar{p}p}$. We discuss the theoretical aspects of this formalism and consider the phenomenological implications of a class of energy-dependent form factors in the high-energy behavior of the forward amplitude. We introduce integral dispersion relations specially tailored to relate the real and imaginary parts of eikonals with energy-dependent form factors. Our results, obtained using a group of updated sets of parton distribution functions (PDFs), are consistent with the recent data from the TOTEM, AUGER and Telescope Array experiments.