Grant-in-Aid for international Scientific Research
|Allocation Type||Single-year Grants |
|Research Institution||Faculty of Science, Osaka City University |
ITO Nobuo Osaka City University Professor, 理学部, 教授 (10047045)
MONDAL N.K. タタ研究所, 物理部, 講師
KRISHNASWAMY タタ研究所, 物理部, 助教授
NARASIMHAM V タタ研究所, 物理部, 教授
SREEKANTAN B タタ研究所, 物理部, 特任教授
MENON M.G.K. タタ研究所, 物理部, 名誉教授
HAYASHI Yoshio Osaka City University, Lecturer, 理学部, 講師 (00106337)
KAWAKAMI Saburo Osaka City University, Associate Professor, 理学部, 助教授 (40047337)
MIYAKE Saburo Kanagawa University, Professor, 工学部, 教授 (50013339)
N. K. Mondal Tata Institute of Fundamental Research, Fellow
M. R. Krishnaswamy Tata Institute of Fundamental Research, Senior Fellow
V. S. Narasimham Tata Institute of Fundamental Research, Professor
B. V. Sreekantan Tata Institute of Fundamental Research, National Professor
M. G. K. Menon Tata Institute of Fundamental Research, Professor Emeritus
|Project Period (FY)
1988 – 1990
Completed (Fiscal Year 1990)
|Budget Amount *help
¥6,000,000 (Direct Cost: ¥6,000,000)
Fiscal Year 1990: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1989: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1988: ¥2,000,000 (Direct Cost: ¥2,000,000)
|Keywords||Great underground depth. / Cosmic rays. / Prompt muons. / Multiple muons. / Celestial Sources of neutrino. / Massive long lived particles. / Monopole. / Proton decay.|
Three large calorimetric type detector have been operated at great depth of 6,045 and 7,000 hg/cm^2 at the Kolar Gold Mines. The results so far obtained are as follows ;
1. Angular distribution, depth-Intensity relation and Energy Spectrum of muons have been studied very precisely as fundamental quantity of the muon energy up to 250 TeV.
2. Prompt Muon Production ; The zenith angular distribution of atmospheric muons have been analzsed in order to study the production of prompt muons in high energy (>50 TeV) of primary cosmic ray interactions. The present data indicates that with gamma=2.7 for muon energy of 8-250 TeV, there is prompt muon production at the level of X=(0.9<plus-minus>0.2)X10^<-3>.
3. Multiple Parallel Muons ; Multiplicity, decoherence and special type of muon bundles have been examined. An unusually high multiplicity (Nmu=20) muon bundle was observed at a depth of 6,045 hg/cm^2.
4. High Energy Nutrinos from Celestial Sources ; K. G. F. Nucleon decay detectors have been used to look for neutrino induced muons from celestial potential potential sources.
5. Massive Long Lived Particles ; within the category of Neutrino events, there exist some special type of events which show possible evidence for the existence of long lived massive particles. Decay mode, life time and mass of particles have been examined.
6. Magnetic Monopole ; A search has been made for the GUT monopole with the method of a) ionization b) progressive time delay and c) catalysis of nucleon decay.
7. Nucleon Decay ; In a total exposure of 1,100 ton years, 11 candidate events for nucleon decay have been recorded. Lifetime of nucleons bounded in iron nuclei is estimated as T_N-3.1X10^<31> years.