A measurement of the contribution of the gluon to the spin of the nucleon

This dissertation presents the results of an investigation into the contribution to the spin of the nucleon from the gluons mediating the strong force within the nucleon. The experimental data was obtained using the HERMES instrument at the Deustches Elektronen-Synchroton (DESY) in Hamburg, Germany during the year 2000. The effort was motivated by an earlier observation at HERMES that not all of the spin could be attributed to the quarks making up the nucleon The approach utilized in the work reported herein was to employ the polarized gas target at HERMES to provide a polarized target of nucleons and then to probe the attendant polarization of the gluons with the polarized positron beam of the experiment. This was accomplished by seeking evidence of photon-gluon fusion (PGF) deep inelastic scattering events in the form of elementary particles resulting from the decay of charmed particles, which were known to be unique indicators of PGF. Best results indicate ΔG/G = 0.131± 0.164 (stat.) ± 0.131(syst.) at xg = 0.35 and Q2 = 0.18, a result consistent with zero or a slightly positive value.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Year dc:date

2012

Author dc:creator

• Bailey, Paul Spencer

Contributors dc:contributor

• Makins, Naomi C.R.

• gluons
• HERMES
• photon-gluon fusion (PGF)
• Bose-Einstein condensates
• Monte Carlo Simulation (MCS)

Statement dc:rights

• © 2006 Paul Spencer Bailey

Language dc:language

en

Identifier

5384553

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/31908