Jets and Energy Flow in Photon-Proton Collisions at HERA

TL;DR

This paper investigates the properties of hadronic final states in photon-proton collisions at HERA, comparing experimental data with QCD models to understand jet production and underlying event energy.

Contribution

It provides the first detailed comparison of photon-proton collision data with QCD models including beam remnant interactions, enhancing understanding of hadronic final states.

Findings

QCD models with beam remnant interactions describe data well

Differential jet cross sections are measured accurately

Photon-proton events show similar features to proton-antiproton collisions

Abstract

Properties of the hadronic final state in photoproduction events with large transverse energy are studied at the electron-proton collider HERA. Distributions of the transverse energy, jets and underlying event energy are compared to $\overline{p}p$ data and QCD calculations. The comparisons show that the $\gamma p$ events can be consistently described by QCD models including -- in addition to the primary hard scattering process -- interactions between the two beam remnants. The differential jet cross sections $d\sigma/dE_T^{jet}$ and $d\sigma/d\eta^{jet}$ are measured.