Proton opacity in the light of LHC diffractive data

TL;DR

This paper models proton scattering data from the LHC using a 3-channel eikonal approach linked to QCD, showing that absorptive effects significantly influence rapidity gap measurements and align well with ATLAS data.

Contribution

It introduces a parameter-free 3-channel eikonal model based on a single Pomeron linked to QCD, effectively describing elastic scattering and rapidity gap data.

Findings

Model accurately describes LHC elastic scattering data.

Absorptive effects significantly impact rapidity gap cross sections.

Parameter-free calculations agree with ATLAS measurements.

Abstract

We show that collider data on elastic pp (and p\bar{p}) scattering, including the LHC TOTEM data at 7 TeV, can be well described by a 3-channel eikonal model with only one Pomeron, with parameters that are naturally linked to the perturbative QCD (BFKL) framework. The proton opacity, determined in this way, is then used to account for sizeable absorptive effects. We study the recent measurements of d\sigma/d\Delta\eta made by the ATLAS collaboration, where they select events with large rapidity gaps \Delta\eta. We demonstrate that the absorptive corrections noticeably change both the value and the \Delta\eta dependence of the cross section. We find that our parameter-free calculation is in agreement with these ATLAS data.