Rapidity gap distribution in diffractive deep-inelastic scattering and parton genealogy

TL;DR

This paper introduces a partonic model for high-mass diffractive events in onium-nucleus scattering, predicting gap size distributions and linking them to branching random walk decay times, supported by numerical and Monte Carlo simulations.

Contribution

It presents a novel partonic framework connecting diffractive gap distributions to branching random walk decay times, validated through numerical solutions and Monte Carlo simulations.

Findings

Predicted gap size distribution matches numerical solutions of BK equations.

Monte Carlo simulations support the proposed partonic picture.

The distribution is linked to the decay time of a common ancestor in branching processes.

Abstract

We propose a partonic picture for high-mass diffractive dissociation events in onium-nucleus scattering, which leads to simple and robust predictions for the distribution of the sizes of gaps in diffractive dissociation of virtual photons off nuclei at very high energies. We show that the obtained probability distribution can formally be identified to the distribution of the decay time of the most recent common ancestor of a set of objects generated near the edge of a branching random walk, and explain the physical origin of this appealing correspondence. We then use the fact that the diffractive cross section conditioned to a minimum rapidity gap size obeys a set of Balitsky-Kovchegov equations in order to test numerically our analytical predictions. Furthermore, we show how simulations in the framework of a Monte Carlo implementation of the QCD evolution support our picture.