pp elastic scattering at ISR and LHC energies

TL;DR

This paper analyzes elastic proton-proton scattering data from ISR to LHC energies using a complex amplitude model, revealing a two-layer proton structure and significant changes at higher energies.

Contribution

It introduces an analytical amplitude model with three exponentials and complex phases, accounting for Coulomb effects and perturbative contributions, to describe scattering data across energies.

Findings

Detected a two-layer structure of protons.

Observed a sharp increase in the inner layer at 13 TeV.

Identified significant amplitude behavior changes from ISR to LHC energies.

Abstract

We describe data on elastic $pp$ scattering at ISR and LHC energies using the analytical representation of the amplitude as the sum of three exponentials equipped with complex phases. In addition, we take into account the Coulomb and Coulomb-nuclear contributions in the entire transfer region and strong "perturbative" contributions in the large transfer region. Refined values of basic scattering characteristics are obtained. Significant changes in the behavior of the amplitude are detected at the transition from ISR to LHC energies. The results obtained indicate a two-layer structure of the colliding protons. In the transition to 13 TeV, a sharp increase in the size of the inner layer and its activity in the scattering is observed. A possible interpretation of this effect is discussed.