Date of Award
Doctor of Philosophy (PhD)
Nuclear & Particle Physics
Charles E. Hyde
This experiment investigates the deep virtual production of both σ− and ρ− mesons, with a particular focus on the microscopic structure of the σ mesons. While the ρ meson is an ordinary qq¯ pair, the σ meson is composed of not only the typical qq¯ pair, making it a topic of controversy for nearly six decades. Although the existence of the σ− meson is now well established, its microscopic structure remains poorly understood. The primary objective of this thesis is to contribute to the understanding of the σ meson by analyzing its deep virtual production. The main focus of this study was on the ep → e ′p ′π +π − reaction, which is a crucial process for investigating both the σ− and ρ− mesons. Specifically, this reaction is sensitive to the pure glue component of the σ− meson’s wave function near the threshold in the ππ− system. In order to separate the σ− and ρ− meson channels, we analyzed the angular distribution in the ππ rest frame. By focusing on this reaction and employing this technique, we aimed to gain a better understanding of the structure of both the σ− and ρ− mesons. The model has developed according to Lehmann-Dronke to understand the σ− and ρ− mesons separately. To conduct our experiment, we chose to use the data from the Hall B CLAS12 “Run Group A” with an electron beam energy of 10.6 GeV incident on the LH2 target. The CLAS12 detector in Hall B has a large acceptance, making it an ideal choice for our study. By using this data, we were able to obtain accurate and reliable measurements of the ep → e ′p ′π +π − reaction and further our understanding of the σ− and ρ− mesons.
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Bulumulla, Dilini L..
"Deep Virtual Pion Pair Production"
(2023). Doctor of Philosophy (PhD), Dissertation, Physics, Old Dominion University, DOI: 10.25777/j3ch-t691