| Project/Area Number |
13640288
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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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 | The University of Tokyo |
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Principal Investigator |
TAKITA Masato The University of Tokyo, Institute for Cosmic Ray Research, Associate Professor, 宇宙線研究所, 助教授 (20202161)
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| Co-Investigator(Kenkyū-buntansha) |
HAZUMI Masashi High Energy Accelerator Research Organization, Institute of Particle and Nuclear Studies, Associate Professor, 素粒子原子核研究所, 助教授 (20263197)
HARA Takanori Osaka University, Graduate School of Science, Research Associate, 理学研究科, 助手 (70283827)
OHNISHI Munehiro The University of Tokyo, Institute for Cosmic Ray Research, Associate, 宇宙線研究所, 助手 (10260514)
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| Project Period (FY) |
2001 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2003: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 2002: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2001: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | Super-Kamiokande / upward-going muons / atmospheric neutrinos / southern sky hemisphere / AGN / point sources |
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| Research Abstract |
We search for celetial neutrino point sources in the southern sky hemisphere by neutrino induced upward-going muon detected with the Super-Kamiokande detector. Search for neutirno signal from active galactic nuclei (AGN) is particularly interesting. The major background of atmosperic neutrino origin below 100 GeV is estimated to be 0.05 events/year. We have accumulated approximately 2000 neutirino induced upward-going muon events during 1600 detector live days from 1996 to 2001. We perform a Monte Carlo simulation as well as an analytic calculation of neutrino events, assuming AGN neutrino sources. Other analysis software are developed whenever needed. We spend our time extensively on the development of an automatic event reconstruction program of through-going and stopping muons in the Super-Kamiokande detector. The expected number of upward-going muons induced by atmospheric neutrinos is estimated to be roughly 2000 events which is reasonably consistent with the observed number. We plot the observed upward-going muon events in the celestial coordinates and study the event density distribution. We check whether there exists excess of upward-going events from acelecial point sources againt the atmospheric neutrino background events. However, we find no statistically significant excess in the southern sky hemisphere. Accordingly, we set the most stringent upper limit of 10^<-14>/cm^2/s at 90% confidence level on neutrino-induced upward-going muons from celetial point sources.
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