pp Elastic Scattering at LHC Proton Structure Outer Cloud - Inner Shell - Gluon Core

TL;DR

This paper proposes a detailed multi-region model of the proton structure, explaining elastic scattering processes at high energies, and successfully matches experimental data from LHC and Tevatron experiments.

Contribution

It introduces a novel four-region proton model and identifies a new elastic scattering process involving boundary collisions, with parameters fitted to recent high-energy scattering data.

Findings

The model accurately describes 13 TeV pp scattering data.

Identifies a new elastic scattering process at the proton boundary.

Matches experimental data without oscillations at large |t|.

Abstract

Our investigation of high energy $\rm{pp}$ and $\bar{\rm{p}}\rm{p}$ elastic scattering over the last two decades has led us to consider that the proton has three regions: i) an outer region consisting of a quark-antiquark ($\rm{q}\bar{\rm{q}}$) condensate ground state (also described as quark-antiquark outer cloud), ii) an inner shell of baryonic charge of size ~0.44 fm, and iii) a core of size ~0.2 fm, where the three valence quarks of a proton with baryonic charges are confined. The proton structure that has emerged leads to four main elastic scattering processes in $\rm{pp}$ scattering. The first process, which gives rise to diffraction scattering, is due to a glancing collision of the outer cloud of one proton with that of another proton. In a $\bar{\rm{p}}\rm{p}$ glancing collision the corresponding process occurs. The second process involves multiple \omega-exchanges. The third process in $\rm{pp}$ scattering is quark-quark scattering via gluon-gluon interaction. The fourth process - which appears for the first time in our investigation of $\rm{pp}$ scattering - is a glancing collision at the boundary of a proton cloud with that of the other proton cloud. To describe quantitatively the four processes, their parameters have been determined. For this purpose, we investigated $\rm{pp}$ 7 TeV d\sigma/dt measured by the TOTEM Collaboration and $\bar{\rm{p}}\rm{p}$ 1.96 TeV d\sigma/dt measured by the D0 Collaboration. Our calculated $\rm{pp}$ elastic d\sigma/dt at 13 TeV has no oscillations in the large |t| region, in good agreement with the preliminary TOTEM measurements.