A First Study of Multijet Dynamics in Hard Photoproduction at HERA

Strickland, Esther Joanne (1998) A First Study of Multijet Dynamics in Hard Photoproduction at HERA. PhD thesis, University of Glasgow.

Abstract

The cross section for the photoproduction of events containing three high transverse energy jets with a three-jet invariant mass of M3J > 50 GeV has been measured with ZEUS at HERA. The data are compared with two different types of QCD prediction; O(alphaalpha2S) pQCD calculations which are leading order for the process under consideration and parton shower models which resum leading logarithms to produce multi-parton final states. The magnitude of the three-jet cross section is in good agreement with the O(alphaalpha2S) pQCD calculations; the parton shower models underestimate the cross section by 20 to 40%. The angular distribution of the three jets is inconsistent with a uniform population of the available phase space. In contrast, parton shower models and O(alphaalpha2S) pQCD calculations are able to describe the three-jet dynamics. Within the parton shower model the relative contribution to three-jet production from initial and final state radiation has been studied and the effect of colour coherence on the angular distribution is demonstrated for the first time.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Adviser: Peter Bussey
• Keywords: High energy physics
• Date of Award: 1998
• Depositing User: Enlighten Team
• Unique ID: glathesis:1998-75894
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 19 Nov 2019 17:39
• Last Modified: 19 Nov 2019 17:39
• URI: https://theses.gla.ac.uk/id/eprint/75894