Diffraction at the LHC

TL;DR

This paper demonstrates that a two-channel eikonal model with an energy-dependent pomeron coupling can successfully describe various diffractive scattering data from CERN-ISR to LHC energies, including the low-mass diffraction observed at the LHC.

Contribution

The study introduces an energy-dependent coupling in a two-channel eikonal model to accurately describe diffractive scattering data across a wide energy range, explaining the low LHC diffraction measurements.

Findings

Successful description of total, elastic, and diffractive cross sections from CERN-ISR to LHC.

Explanation of the low LHC diffractive cross section using energy-dependent pomeron coupling.

Calculation of the rapidity gap survival probability sensitive to diffractive eigenstate structure.

Abstract

We show that the diffractive pp (and p\bar{p}) data (on \sigma_tot, d\sigma_el/dt, proton dissociation into low-mass systems, \sigma^D(low M), and high-mass dissociation, d\sigma/d(\Delta\eta)) in a wide energy range from CERN-ISR to LHC energies, may be described in a two-channel eikonal model with only one `effective' pomeron. By allowing the pomeron coupling to the diffractive eigenstates to depend on the collider energy (as is expected theoretically) we are able to explain the low value of \sigma^D(low M) measured at the LHC. We calculate the survival probability, S^2, of a rapidity gap to survive `soft rescattering'. We emphasize that the values found for S^2 are particularly sensitive to the detailed structure of the diffractive eigenstates.