Diffractive Gluon Production in Proton-Nucleus Collisions and in DIS

TL;DR

This work derives quasi-classical expressions for diffractive gluon production in proton–nucleus collisions and in DIS by resumming all multiple rescatterings in the target field, using color-singlet projectile models (qar q for onium and qqq for the proton). It provides explicit diffractive cross sections built from forward propagators through the nucleus, including the qar qG and qqqG states and the role of spectator partons, and extends the framework to DIS to produce both diffractive and inclusive gluon production formulas. The results highlight the influence of the saturation scale $Q_s^2$ and the color structure of the projectile on diffraction, offering analytic or semi-analytic expressions usable for RHIC/HERA kinematics within the saturation paradigm. Overall, the paper furnishes a self-contained quasi-classical approach to diffractive and inclusive gluon production in high-energy hadronic and lepton–hadron collisions.

Abstract

We derive expressions for the gluon production cross sections in the single diffractive proton-nucleus scattering and DIS processes in a quasi-classical approximation. The resulting cross sections include the effects of all multiple rescatterings in the classical background field of the target proton or nucleus, which remains intact after the scattering. We also write down an expression for the inclusive gluon production cross section in DIS in the quasi-classical approximation.

Figures (6)

• Figure 1: Diagrams contributing to the diffractive gluon production cross section in the quarkonium-nucleus scattering.
• Figure 2: Diagrams included in a diffractive scattering of the $q{\bar{q}}G$ state on a single nucleon in the target nucleus.
• Figure 3: Diffractive gluon production in proton-nucleus scattering (pA).
• Figure 4: Diagrams contributing to the interaction of the proton with a nucleon in the target nucleus.
• Figure 5: Three possible ways of generating a $qqqG$ fluctuation in a proton.