Fluctuations, Saturation, and Diffractive Excitation at low x

TL;DR

This paper unifies the description of diffractive excitation at low and high masses using the Good-Walker formalism, incorporating BFKL ladder fluctuations and saturation effects, and estimates the triple-pomeron coupling.

Contribution

It introduces a unified approach to diffractive excitation across mass ranges by including BFKL ladder fluctuations and saturation effects within the Good-Walker formalism.

Findings

Fluctuations in the BFKL ladder can describe both low and high mass excitation.

Saturation suppresses fluctuations in high-energy pp collisions.

The Dipole Cascade Model reproduces the triple-Regge form and estimates the triple-pomeron coupling.

Abstract

Diffractive excitation is usually described by the Good--Walker formalism for low masses, and by the triple-Regge formalism for high masses. In the Good-Walker formalism the cross section is determined by the fluctuations in the interaction. By taking the fluctuations in the BFKL ladder into account, it is possible to describe both low and high mass excitation in the Good-Walker formalism. In high energy pp collisions the fluctuations are strongly suppressed by saturation, which implies that pomeron exchange does not factorise between DIS and pp collisions. The Dipole Cascade Model reproduces the expected triple-Regge form for the bare pomeron, and the triple-pomeron coupling is estimated.