The large number of scalar meson states below 2 GeV contradicts the expected number derived from a quark-antiquark description. One possibility is that one or more of the light scalar mesons can be described as four quark states composed of quark-antiquark pairs. This scenario has been explored with sum-rule methods in Quantum Chromodynamics (QCD) to leading-order in the strong coupling constant. Higher loop contributions are significant in the QCD sum-rule analysis of quark-antiquark scalar states and a similar situation could occur in the four-quark case. In this thesis the leading order and pieces of the second order terms of the correlation function, as needed to study properties of a four-quark state via a QCD sum-rule, is calculated in the chiral limit (i.e. massless quarks) in QCD. Operator mixing related to renormalization of the composite operators appearing in the correlation function first contributes at second order. The result for the second order contributions to the correlation function indicate that operator mixing must be addressed before using proper dispersion relations to link this calculation with the mass of an existing state.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:SSU.etd-12052007-134418 |
| Date | 06 December 2007 |
| Creators | Mihilewicz, Kris Anthony |
| Contributors | Spiteri, Raymond J., Pywell, Robert E., Koustov, Alexandre V. (Sasha), Dick, Rainer, Steele, Tom G., Tanaka, Kaori |
| Publisher | University of Saskatchewan |
| 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 | text |
| Format | application/pdf |
| Source | http://library.usask.ca/theses/available/etd-12052007-134418/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Saskatchewan or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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