Dijet Angular Distributions in Direct and Resolved Photoproduction at HERA

Abstract

Jet photoproduction, where the two highest transverse energy ($\ETJ$) jets have $\ETJ$ above 6 GeV and a jet-jet invariant mass above 23~GeV, has been studied with the ZEUS detector at the HERA $ep$ collider. Resolved and direct photoproduction samples have been separated. The cross section as a function of the angle between the jet-jet axis and the beam direction in the dijet rest frame has been measured for the two samples. The measured angular distributions differ markedly from each other. They agree with the predictions of QCD calculations, where the different angular distributions reflect the different spins of the quark and gluon exchanged in the hard subprocess.

20 pages including 4 figures

References in corpus (2)

• A Measurement of the Proton Structure Function $F_2(x,Q^2)$
• Dijet Cross Sections in Photoproduction at HERA

Cited by in corpus (23)

• Jet photoproduction at HERA
• HERA Collider Physics
• Theory of hard photoproduction
• Survey of present data on photon structure functions and resolved photon processes
• Dijet Rapidity Gaps in Photoproduction from Perturbative QCD
• Substructure dependence of jet cross sections at HERA and determination of alphas
• Photoproduction of jets at HERA in next-to-leading order QCD
• Experimental Aspects of Jet Physics at a Future EIC
• High-mass dijet cross sections in photoproduction at HERA
• Observation of Isolated High-ET Photons in Photoproduction at HERA
• Measurement of the Inclusive Di-Jet Cross Section in Photoproduction and Determination of an Effective Parton Distribution in the Photon
• Measurement of Three-jet Distributions in Photoproduction at HERA
• Low Q^2 Jet Production at HERA and Virtual Photon Structure
• Dijet angular distributions in photoproduction of charm at HERA
• Mapping the proton unintegrated gluon distribution in dijets correlations in real and virtual photoproduction at HERA
• Photon structure studied at an Electron Ion Collider
• High-E_T dijet photoproduction at HERA
• High Energy Photoproduction
• Soft Particle Emission Accompanying Dijet Photoproduction
• Two Photon Physics at LEP2; including data Monte-Carlo comparison
• Jet Cross Sections at HERA - Current Issues
• A Global Study of Photon-Induced Jet Production
• Inclusive hard processes in photon-photon and photon-proton interactions