Three-jet production in diffractive deep inelastic scattering at HERA

TL;DR

This study analyzes three-jet production in diffractive deep inelastic scattering at HERA, revealing jet broadening patterns consistent with gluon and quark production models, using ZEUS detector data.

Contribution

First measurement of three-jet production in diffractive DIS at HERA, providing detailed differential cross sections and insights into parton dynamics.

Findings

Jets in the Pomeron direction are broader than in the photon direction.

Results support models with gluons in the Pomeron and quarks in the photon direction.

Differential cross sections align with theoretical predictions.

Abstract

Three-jet production in the reaction ep --> eXp has been studied with the ZEUS detector at HERA using an integrated luminosity of 42.74 pb^-1. The data were measured in the kinematic region 5 < Q^2 < 100 GeV^2, 200 < W < 250 GeV and 23 < M_X < 40 GeV. The diffractive signal was selected by requiring a large rapidity gap in the outgoing proton direction. Jets were reconstructed in the centre-of-mass system of X using the exclusive k_T-algorithm. A sample of three-jet events in diffraction has been identified. Differential cross sections were measured as a function of the jet pseudorapidity and jet transverse momentum with respect to the virtual photon-Pomeron axis. The jets going in the Pomeron direction are broader than those going in the virtual-photon direction. This is consistent with models predicting that gluons are predominantly produced in the Pomeron direction and quarks in the virtual-photon direction.