| Project/Area Number |
08640343
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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 | Tohoku University |
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Principal Investigator |
HIKASA Ken-ichi Tohoku University, Dept.of Physics, Professor, 大学院・理学研究科, 教授 (20208739)
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| Co-Investigator(Kenkyū-buntansha) |
SUMINO Yukinari Tohoku University, Dept.of Pyhsics, Assistant, 大学院・理学研究科, 助手 (80260412)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1997: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1996: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | Supersymmetry / Electron-positron collisions / Linear collider / Top quark / Symmetry breaking / QCD / Helicify amplitude / Automatic calculation / トップクォーク / テクニカラー / 量子電気力学 |
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| Research Abstract |
1.We study three-body decays of charginos in supersymmetry and examine the dependence of the branching ratios on the mass of scalar quarks and leptons. We find that the ratio of electronic and tauonic branching ratio can have a large deviation from one if the chargino is gaugino-like. This measurement should be useful to obtain information on slepton masses and therefore a key to the mechanism of supersymmetry breaking.
2.In the gauge mediated scenario of supersymmetry breaking, superparticles eventually decay to a gravitino, which has a spin 3/2. We develop a formalism to calculate helicity amplitudes for processes containing spin 3/2 particles. Some decay processes with a gravitino in the initial or final state are calculated.
3.We develop a compute code which generates programs to calculate cross sections for superparticle production processes (with two or three body final states) in e^+e^- collisions.
4.We study the effect of final state interaction due to gluon exchange on the energy and angular distributions of final leptons in top production in e^+e^- collisions. The distributions change by ten percent due to this effect. We also calculate the second order correction to the QCD potential which is related to the top production process. We find that the result changes according to whether the renormalization group equation is solved in the momentum or the configuration space. This ambiguity gives a 6% error to the cross section.
5.We apply the N/D method developed for the strongly interacting Higgs sector to pipi scattering and find a result suggestive of the existence of the sigma meson.
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