Photoproduction events in ep collisions with photon virtuality Q2, the negative squared four-momentum of the exchanged photon, less than 1 GeV2, and at least two jets of high transverse energy have been studied in the photon and proton center-of-mass range Wgp of 134 < Wgp < 277 GeV with the ZEUS detector at HERA. The data sample was collected during the 1996 and 1997 running periods with an integrated luminosity of 38.7 pb-1 allowing for a precise measurement of differential cross sections in a kinematic regime unreachable for experiments at current e+e- colliders. For the determination of these differential cross sections, both jets were required to have a transverse energy larger than 11 GeV with at least one having more than 14 GeV. Differential hadron cross sections were extracted for these dijet events using separate resolved and direct enhanced subsamples. The cross sections have been compared to NLO QCD calculations using several different parametrisations of the photon structure functions within these calculations. The achieved sensitivity of the data at the photon structure functions allows to test the validity of the used parametrisations of the photon structure functions. This test shows the need for improvements of those parametrisations in the kinematical range under investigation. The extracted data at low xOBSg constrains the parton densities in the photon which can be exploited in future parametrisations of the photonic parton densities.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.83085 |
| Date | January 2002 |
| Creators | Ochs, Andreas H. |
| Contributors | Corriveau, Francois (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Physics.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001985030, proquestno: AAINQ88545, Theses scanned by UMI/ProQuest. |
Page generated in 0.0018 seconds