ePubs
The open archive for STFC research publications
Home
About ePubs
Content Policies
News
Help
Privacy/Cookies
Suggest an Enhancement
Contact ePubs
Full Record Details
Persistent URL
http://purl.org/net/epubs/work/29677
Record Status
Checked
Record Id
29677
Title
Quantum Chromodynamics with the OPAL Detector at LEP
Contributors
D E Hutchcroft
Abstract
Quantum Chromodynamics is the study of the interactions of the strong force, which is one of the 3 forces in the Standard Model. I have studied several properties of the hadronic final states of e(+)e(-) annihilations with the OPAL detector. The OPAL detector is one of the four detectors on the LEP ring at CERN. As a nearly 4pi detector OPAL can fully reconstruct the hadronic final states of the e(+)e(-) collisions. Two matrix based methods for correcting the resolution and efficiency effects of the detector are compared. One of the methods is based upon the singular value decomposition of a matrix and the other is based upon Bayes' theorem. Both of the methods can reconstruct the underlying distribution from a measured distribution and an estimate of the detector effects. A measurement of the longitudinal cross-section for the decay of Z(0) --> hadrons is made, giving the result sigma(L)/sigma(tot)=0.0127+/-0.0016+/-0.0017. This measurement can be used with a theoretical calculation of longitudinal cross-section to measure a value of the strong coupling, alpha(s)(M(Z(0)))=0.126+/-0.016+/-0.017. The OPAL data for LEP 1 (sqrt(s)=M(Z(0))) and LEP 2 (sqrt(s)=161, 172 and 183 GeV) are used to measure some of the event shape distributions at these energies. The distributions and their moments, at LEP 1, or their means, widths and skewnesses, at LEP 2, are presented. These measurements are compared with several Monte Carlo models. These models show good agreement with the data at all of the energies. The data are also fitted to combined O(alpha(s)(2))+NLLA calculations of the event shape distributions. These are used to fit for the value of the strong coupling giving alpha(s)(M(Z(0)))=0.1150(+0.0075)(-0.0065), when fitted for 5 event shapes at 4 energies simultaneously. The possibility of a fixed value for the strong coupling can be excluded at the 96% confidence level.
Organisation
CCLRC
Keywords
Funding Information
Related Research Object(s):
Licence Information:
Language
English (EN)
Type
Details
URI(s)
Local file(s)
Year
Thesis
RAL Theses
RAL-TH-1998-007. 1998.
1998
Showing record 1 of 1
Recent Additions
Browse Organisations
Browse Journals/Series
Login to add & manage publications and access information for OA publishing
Username:
Password:
Useful Links
Chadwick & RAL Libraries
SHERPA FACT
SHERPA RoMEO
SHERPA JULIET
Google Scholar