| Project/Area Number |
23540347
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Particle/Nuclear/Cosmic ray/Astro physics
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| Research Institution | Toho University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
MIKADO Shoji 日本大学, 生産工学部, 准教授 (80408947)
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| Co-Investigator(Renkei-kenkyūsha) |
OGAWA Satoru 東邦大学, 理学部, 教授 (10256761)
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| Research Collaborator |
FUKUDA Tsutomu 東邦大学, 理学部, 博士研究員 (10444390)
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| Project Period (FY) |
2011 – 2013
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| Project Status |
Completed (Fiscal Year 2013)
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| Budget Amount *help |
¥5,200,000 (Direct Cost: ¥4,000,000、Indirect Cost: ¥1,200,000)
Fiscal Year 2013: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2012: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
Fiscal Year 2011: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
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| Keywords | 素粒子実験 / エマルション / 磁場 / ニュートリノ / ECC |
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| Research Abstract |
The OPERA experiment has found 4 tau-neutrino candidate events. 3 out of the 4 events are in hadronic decay channels of the tau lepton, where a hadron interaction could be a source of background. We therefore studied hadron interactions in an OPERA-like emulsion/lead target. We have found that they are well reproduced by a Monte Carlo simulation (MC) and have validated MC estimation of the background due to hadron interactions in the sample of tau decay candidates. As a result, the neutrino oscillations have been established with a significance of 4.2 sigma. We made emulsion detectors with springs and performed a test beam experiment. Appropriate strength of springs was obtained together with knowledge of brick handling. New techniques on a photomask to correct deformations in emulsion and on automatic scanning with wide-angle acceptance were successfully developed. These techniques will be applied in future neutrino experiments with emulsion spectrometers.
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