Format:
Online-Ressource (XIII, 123 p. 86 illus., 48 illus. in color, online resource)
Edition:
1st ed. 2016
ISBN:
9789811000126
Series Statement:
Springer Theses, Recognizing Outstanding Ph.D. Research
Content:
Introduction to Pentaquark Search -- Experimental Apparatus -- Data Analysis -- Results -- Discussion -- Conclusion -- Appendix.
Content:
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.
Note:
"Doctoral thesis accepted by Kyoto University, Kyoto, Japan
,
Includes bibliographical references
Additional Edition:
ISBN 9789811000102
Additional Edition:
Erscheint auch als Druck-Ausgabe ISBN 978-981-10-0010-2
Language:
English
Keywords:
Pentaquark
;
Hochschulschrift
DOI:
10.1007/978-981-10-0012-6
URL:
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