Double non-perturbative gluon exchange: an update on the soft Pomeron contribution to pp scattering

TL;DR

This paper investigates the role of double non-perturbative gluon exchange in modeling the soft sector of proton-proton scattering, comparing various gluon propagator models with experimental data.

Contribution

It introduces updated non-perturbative gluon propagator models to improve the description of soft pp scattering data, incorporating recent theoretical developments.

Findings

Better agreement with data at lower energies

Different gluon propagator models yield comparable results

Insights into non-perturbative QCD effects in soft scattering

Abstract

We employ a set of recent, theoretically motivated, fits to non-perturbative unquenched gluon propagators to check in how far double gluon exchange can be used to describe the soft sector of pp scattering data (total and differential cross section). In particular, we use the refined Gribov--Zwanziger gluon propagator (as arising from dealing with the Gribov gauge fixing ambiguity) and the massive Cornwall-type gluon propagator (as motivated from Dyson-Schwinger equations) in conjunction with a perturbative quark-gluon vertex, next to a model based on the non-perturbative quark-gluon Maris-Tandy vertex, popular from Bethe-Salpeter descriptions of hadronic bound states. We compare the cross sections arising from these models with "older" ISR and more recent TOTEM and ATLAS data. The lower the value of total energy \sqrt{s}, the better the results appear to be.