Semi-inclusive Lambda electroproduction in the target fragmentation region at CLAS

Phillips, Jeffrey John (2015) Semi-inclusive Lambda electroproduction in the target fragmentation region at CLAS. PhD thesis, University of Glasgow.

Abstract

Studies into the spin structure of the proton have been an active area
of research after the EMC experiment and others found that only 30%
of the total proton spin is carried by the valence quarks. Hadron production in Semi-Inclusive Deep Inelastic Scattering (SIDIS) is one way to study this phenomenon and is the focus of this thesis, which describes the measurement of the polarisation of the Lambda. Hadron production is generally examined in the Current Fragmentation Region (CFR), where the detected hadron
originates from the struck quark, in terms of parton distribution and fragmentation functions. Conversely in the Target Fragmentation Region
(TFR), the hadron is produced in the fragmentation of the target
remnants. In this region the process is described by Fracture Functions which represent the joint probability of producing the final hadron from the target remnants when a parton of the target nucleon is struck by the virtual photon. We propose to aid in the understanding of these functions by extracting the transferred polarisation of Lambda in the SIDIS electroproduction of the hadron from a proton target: ep -> Lambda e' X . In this work, data recorded with the CLAS detector system at Thomas Jefferson National Laboratory during the e1f experimental run with a longitudinally polarised beam on an unpolarised target were analysed. The polarisation of the Lambda has been extracted by using the Maximum Likelihood Extraction (MLE) and Beam Spin Asymmetry (BSA) methods.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Subjects: Q Science > QC Physics
• Colleges/Schools: College of Science and Engineering > School of Physics and Astronomy
• Supervisor's Name: Seitz, Dr. Bjoern and Livingston, Dr. Kenneth
• Date of Award: 2015
• Embargo Date: 23 November 2015
• Depositing User: Dr Jeffrey Phillips
• Unique ID: glathesis:2015-7005
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 12 Jan 2016 13:16
• Last Modified: 12 Jan 2016 13:33
• URI: https://theses.gla.ac.uk/id/eprint/7005