We studied the reaction ππ β πβ²πβ²π with a 4.2 GeV incident electron beam in the region of the electroproduction variables QΒ² from 0.7 to 2.2 GeVΒ² and W from 2.0 to 2.6 GeV. The data were taken and analyzed at the Thomas Jefferson National Accelerator Facility. For the first time, we observe the expected t-slope dependence on QΒ² and Ξπ in π vector meson production. We find that the width of the forward π-meson diffraction peak increases rapidly as the interaction time decreases below cΞπ β 1 fm. Within a simple optical model framework, the data show that π meson has a smaller size than the π. The measured π cross-section dependence on QΒ² is in a good agreement with previous measurements and well-described by the phenomenological Pomeron-exchange model. Our cross-section data do not favor the standard Vector Meson Dominance and π π Μ -knockout model predictions. From the angular distribution of the decay π β πΎβΊπΎβ», assuming the π -channel helicity conservation, we extracted the longitudinal-to-transverse cross-section ratio, π , and Vector Meson Dominance scaling parameter, πΒ², which are consistent with the previous measurements and the model expectations. / Ph. D.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/26172 |
| Date | 16 February 2000 |
| Creators | Loukachine, Konstantin |
| Contributors | Physics, Arndt, Richard A., Mizutani, Titzuro, Jenkins, David A., Pitt, Mark L., Ficenec, John R., Smith, Elton |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Dissertation |
| Format | application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
| Relation | loukachine.pdf |
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