Diffractive processes at the LHC

TL;DR

This paper develops a comprehensive model for high energy soft proton-proton interactions at the LHC, incorporating multi-channel components and matching soft to hard QCD processes, with implications for predicting cross sections and rapidity gap survival probabilities.

Contribution

It introduces a novel multi-channel model that unifies soft and hard Pomeron interactions and accounts for absorptive effects, improving predictions for LHC processes.

Findings

Absorptive effects significantly suppress total cross section predictions.

The model accurately describes existing data on soft pp interactions.

Predictions for rapidity gap survival probabilities are provided.

Abstract

We present a model of high energy soft $pp$ interactions that has multi s- and t-channel components, which has been tuned to describe all the available data. The t-channel components allow matching of the soft to the hard (QCD) Pomeron. Absorptive effects are found to be large, and, for example, suppress the prediction of the total $pp$ cross section to about 90 mb at the LHC. We use the model to calculate the survival probability, S^2, of the rapidity gaps in the exclusive process pp \to p+H+p, a process with great advantages for searching for the H \to \bb signal. We consider both eikonal and enhanced rescattering.