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Search for the Pentaquark Θ+ via the π−p → K−X Reaction at J-PARC
This theses reports on an experimental search for an exotic hadron, Θ+(1540) pentaquark, which is a genuine exotic hadron with a five-quark system of uuddsbar. The results of this book support that the existence of Θ+ was strongly constrained. The Θ+ pentaquark was searched for via the π- p → K- X r...
| Clasificación: | Libro Electrónico |
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| Autor principal: | |
| Autor Corporativo: | |
| Formato: | Electrónico eBook |
| Idioma: | Inglés |
| Publicado: |
Singapore :
Springer Nature Singapore : Imprint: Springer,
2016.
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| Edición: | 1st ed. 2016. |
| Colección: | Springer Theses, Recognizing Outstanding Ph.D. Research,
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| Temas: | |
| Acceso en línea: | Texto Completo |
| Sumario: | This theses reports on an experimental search for an exotic hadron, Θ+(1540) pentaquark, which is a genuine exotic hadron with a five-quark system of uuddsbar. The results of this book support that the existence of Θ+ was strongly constrained. The Θ+ pentaquark was searched for via the π- p → K- X reaction using a beam momentum of 2.01 GeV/c at the J-PARC hadron experimental facility, taking advantage of high-statistics and high-resolution compared with previous experiments, some of which claimed the evidence of Θ+. In order to realize a good missing-mass resolution of 2 MeV, the beam spectrometer and superconducting kaon spectrometer were constructed. No clear peak was observed in the missing mass spectrum of the π- p → K- X reaction, and the upper limit of the production cross section was found to be less than 0.28 μb/sr at the 90% confidence level in a mass region of 1500-1560 MeV/c2. This upper limit is an order of magnitude smaller than that of the previous KEK experiment. Compared with a theoretical calculation using the effective Lagrangian approach, the decay width of Θ+ was evaluated. The upper limits on the decay width were estimated to be 0.36 and 1.9 MeV for the Θ+ spin-parity of 1/2+ and 1/2-, respectively. These are quite small for a width of ordinary hadron resonances, and the existence of Θ+ was strongly constrained and is doubtful. |
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| Descripción Física: | XIII, 123 p. 86 illus., 38 illus. in color. online resource. |
| ISBN: | 9789811000126 |
| ISSN: | 2190-5061 |