| Project/Area Number |
15540278
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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 |
Particle/Nuclear/Cosmic ray/Astro physics
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| Research Institution | Okayama University |
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Principal Investigator |
TANAKA Reizaburo Okayama University, Graduate School of Natural Science and Technology, Associate professor (90325077)
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| Co-Investigator(Kenkyū-buntansha) |
SUMINO Yukinari Tohoku University, Graduate School of Science, Assistant professor (80260412)
NAKANO Itsuo Okayama University, Graduate School of Natural Science and Technology, professor (90133024)
津野 総司 岡山大学, 理学部, 特別研究員(PD)
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| Project Period (FY) |
2003 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 2005: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2004: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2003: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | CP violation / anomalous coupling / baryogenesis / top-quark / helicity / hadron collider / Tevatron / LHC / 素粒子実験 / バリオジェネシス |
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| Research Abstract |
The aim of this research is the study of CP violation and anomalous coupling on top-quark decay at CDF experiment. That will lead to the beyond the Standard Model and some knowledge about the baryogenesis of universe. The study on the mechanism of the top-quark production and decay is especially important since the CDF Run-II is expected to produce a lot of top-quark pair creation.
We have developed a method applicable to top-quark semi-leptonic decay although the reconstruction of top-quark spin at hadron collider is not simple. That is called a sine-helicity method, which reconstructs the effective-spin of the top-quark. This method projects lepton direction to the top-quark helicity at top-quark rest system. We have confirmed that the angular distribution of top-quark decay is reproduced that from the polarized top-quark.
We have suggested to apply this new top-quark effective-spin for the study of anomalous coupling at top-quark decay vertex. This method is more sensitive to the anomalous coupling than the familiar beam line base and off-diagonal base definition of top-quark spin axis. We have also studied a method using angular correlation between W-boson and a charged particle. We used a likely-method to analyze lepton+four jets events.
We have also studied the sensitivity of Tevatron and LHC experiments. And we have gotten the conclusion that this mehod will be promising.
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