A central objective of the field of nuclear physics is understanding the fundamental properties of hadrons and nuclei in terms of QCD. In the last decade, a large range of experimental and theoretical methods have been developed to study the nature of quark confinement and the structure of hadrons which are composites of quarks and gluons. One important way to address some questions of hadron physics is studying the electromagnetic form factors of hadrons. The electric and magnetic form factors are related to the distribution of charge and magnetization in hadrons.The internal structure of hyperons, which are a subgroup of hadrons, is a topic of interest of particle physicists. The BES III experiment is one of the few current facilities for studying hadron structure.The Uppsala Hadron Physics group, which is a part of the BES III collaboration, is preparing a proposal for data taking for ΛΣ̄ 0 transition form factors and Σ 0 direct form factors at 2.5 GeV.Aiming the electromagnetic form factors of Σ hyperons, this work contributes to this proposal by simulation study of the e+ e− → ΛΣ̄ 0 and e + e − → Σ 0 Σ̄ 0 reactions. The efficiency and resolution of the electromagnetic calorimeter sub-detector of BES III and kinematic properties of the detected particles are studied in this work. Our final goal is to provide input for the beam time proposal and optimize the future measurement.In the first chapter, the theoretical background including the Standard Model, strong interaction, QCD, and hadrons are studied. In the second chapter, some concepts like the formalism of cross section, relativistic kinematics, and electromagnetic form factors are briefly presented. The third chapter is dedicated to introducing the e + e − → ΛΣ̄ 0 and e + e − → Σ 0 Σ̄ 0 reactions. The BES experiment at BEPC-II is introduced in chapter 4. In chapter 5, the software tools which have been used for this work are introduced. In the sixth chapter, the result of a toy-Monte Carlo study for parameter estimation is presented. The last chapter is dedicated to the results of a full BES software simulation.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:uu-339808 |
| Date | January 2017 |
| Creators | Vaheid, Halimeh |
| Publisher | Uppsala universitet, Kärnfysik |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | FYSAST ; FYSMAS1065 |
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