| Project/Area Number |
02402006
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
核・宇宙線・素粒子
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| Research Institution | University of Tokyo |
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Principal Investigator |
YAMADA Sakue University of Tokyo, Institute for Nuclear Study, Professor, 原子核研究所, 教授 (70011658)
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| Co-Investigator(Kenkyū-buntansha) |
HAMATSU Ryosuke Tokyo Metropolitan Univ., Dept.of Phys., Asst.Professor., 理学部, 助教授 (20087092)
KUZE Masahiro Univ.Tokyo, INS,Research Associate., 原子核研究所, 助手 (00225153)
TOKUSHUKU Katsuo Univ.Tokyo, INS,Research Associate., 原子核研究所, 助手 (80207547)
ISHII Takanobu Univ.Tokyo, INS,Research Associate., 原子核研究所, 助手 (90134650)
OKUNO Hideki Univ.Tokyo, INS,Asst.Professor., 原子核研究所, 助教授 (10013400)
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| Project Period (FY) |
1990 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥16,000,000 (Direct Cost: ¥16,000,000)
Fiscal Year 1992: ¥4,400,000 (Direct Cost: ¥4,400,000)
Fiscal Year 1991: ¥4,200,000 (Direct Cost: ¥4,200,000)
Fiscal Year 1990: ¥7,400,000 (Direct Cost: ¥7,400,000)
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| Keywords | electron-proton collision / HERA / ZEUS experiment / deep inelastice scattering / the standard model / proton structure functions / leptoquark / 未知の相互作用 / ZEUS / ワ-クステ-ション / シミュレ-ション / 励起レプトン / レプトウォ-ク / 輔射補正 / カロリ-メ-タ- / パイプライン / トリガ- |
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| Research Abstract |
We studied possible existence of new interactions in electron-proton collisions at HERA at DESY in Germany by using a multi-purpose detector built in an international collaboration ZEUS.
In the first two years, we completed the construction of ZEUS detector. The high-resolution uranium-scintillator calorimeter was calibrated with cosmic muons and installed into the experimental hall. The first level global trigger system was built with a pipeline technology. RISC workstations were installed at INS for the preparation of physics analyses. Software for physics simulation, data reconstruction and event display had been installed, In order to determine the trigger algorithm, physics events as well as background beam-gas interaction events were extensively generated with Monte Carlo technique by using the workstations. An international collaboration was organized for the simulation in order to obtain huge data sample, mainly with institutes in Canada, Germany and the Netherlands.
In the final year, the electon-proton collision experiment started. It turned out that the trigger studies performed in the preceeding years were very useful. The trigger hardware proved to be extremely flexible and reliable. The energy resolution of the calorimeter was found to be as good as designed. Although the collected amount of data was rather limited (50 nb^<-1>), we measured the proton structure function in new kinematical regions. It was shown that the quark density in the proton increased as the momentum fraction of the proton carried by the quark decreases. A search of leptoquark was performed with the high-momentum transfer neutral-current deep-inelastic events, The lower bound on the leptoquark mass could be set to 170 GeV, in case the coupling strength is the same to the electro-weak interaction.
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