Rapidity gap survival in central exclusive diffraction: Dynamical mechanisms and uncertainties

TL;DR

This paper reviews the mechanisms affecting the probability that rapidity gaps survive in central exclusive diffraction at high energies, highlighting the main suppression factors and uncertainties in current estimates.

Contribution

It provides a detailed analysis of dynamical mechanisms and uncertainties influencing rapidity gap survival in high-energy proton collisions, emphasizing the impact of soft and hard spectator interactions.

Findings

Main suppression from inelastic soft spectator interactions

Moderate suppression from partonic configuration fluctuations

Survival probability drops below 0.01 at LHC energies

Abstract

We summarize our understanding of the dynamical mechanisms governing rapidity gap survival in central exclusive diffraction, pp -> p + H + p (H = high-mass system), and discuss the uncertainties in present estimates of the survival probability. The main suppression of diffractive scattering is due to inelastic soft spectator interactions at small pp impact parameters and can be described in a mean-field approximation (independent hard and soft interactions). Moderate extra suppression results from fluctuations of the partonic configurations of the colliding protons. At LHC energies absorptive interactions of hard spectator partons associated with the gg -> H process reach the black-disk regime and cause substantial additional suppression, pushing the survival probability below 0.01.