| Project/Area Number |
08404013
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
素粒子・核・宇宙線
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
EN'YO Hideto Kyoto University, Department Physics, Associate Professor, 大学院・理学研究科, 助教授 (30213606)
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| Co-Investigator(Kenkyū-buntansha) |
FUNAHASHI Haruhiko Kyoto University, Department Physics, Associate, 大学院・理学研究科, 助手 (00283581)
MURAKAMI Tetsuya Kyoto University, Department Physics, Associate, 大学院・理学研究科, 助手 (50219896)
MASAIKE Akira Fukui Institute of Technology, Professor, 工学部, 教授 (40022587)
CHIBA Junsei KEK, IPNS, Associate Professor, 素粒子原子核研究所, 助教授 (50126124)
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| Project Period (FY) |
1996 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥29,200,000 (Direct Cost: ¥29,200,000)
Fiscal Year 1998: ¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 1997: ¥9,500,000 (Direct Cost: ¥9,500,000)
Fiscal Year 1996: ¥16,500,000 (Direct Cost: ¥16,500,000)
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| Keywords | φ meson / Chiral Symmetry / Nuclear Matter / Nuclear Media Effect / Electron Pair / Invariant Mass / 中粒子 / ガスチェレンコフ |
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| Research Abstract |
In QCD, hadrons are described as a bound state of confined valence quarks which obtained the effective mass due to the spontaneous breaking of the chiral symmetry. This mechanism determines the properties of hadrons in free space, such as the mass and the decay width. If the vacuum structure was changed from that in free space those properties should also change.
This project aims to obtain the first experimental results which can answer whether such theoretical expectations originated from the chiral symmetry restoration are exist or not.
We have completed the spectrometer construction in 1998 by installing the last detectors, the rear gas-Cherenkov counters and the rear EM-calorimeters. In 1997, we have performed the test run focusing only to the φ → KィイD1+ィエD1KィイD1-ィエD1 decay mode. Since 1998, we have started simultaneous data taking runs for both φ → eィイD1+ィエD1eィイD1-ィエD1 and φ → KィイD1+ィエD1KィイD1-ィエD1 decay modes.
The analysis of the 1997 data was completed. The results are reported in several international conferences, and the PhD thesis of Dr. Yokkaichi and the associated paper have bean published. The 1997 data was not statistically enough so that we could only report the nuclear mass-dependence of the φ production. From the 1998-1999 data, however, we could obtain the signature of in-medium decay of φ meson which carries the information of in-medium width and shift of the vector mesons. The results are being reported in several conferences.
This report includes the scientific materials which have been reported so far, and also includes outcomes from the developments of special detectors developed in this project.
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