| Project/Area Number |
13640276
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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 | Nagoya University |
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Principal Investigator |
SANDA Ichiro Nagoya University, Department of Physics, Professor, 大学院・理学研究科, 教授 (60242806)
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| Project Period (FY) |
2001 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2004: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2003: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2002: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2001: ¥900,000 (Direct Cost: ¥900,000)
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| Keywords | CP Violation / Quantum mechanics / B meson / B-Physics / CP非保存 / 素粒子 / 対称性 / B工場 |
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| Research Abstract |
In this project I studied 2 body exclusive decays of B mesons. There are over 70 such decay modes. PQCD approach was used to understand CP violations in these decays.
It has been observed that Br(B→Kπ) is larger than Br(B→ππ), which indicates that there are substantial penguin contributions. As a test of PQCD these branching rations were computed to see if there is natural understanding of penguin enhancement. It is worth emphasizing that penguin annihilation amplitude can be computed in the frame work of PQCD. Thus it is possible to compute the final state strong interaction phase.
The CP violation in B→Kπ and B→ππ has been computed with an estimate of uncertainty coming from computing the strong interaction phase.
It is noted that only penguin diagrams contribute in B→Kψ decay. Thus by computing the branching ratio for this decay, we can critically test the ability of computing the penguin amplitudes using PQCD. It has been shown that indeed PQCD gives a sufficiently accurate estimate of the penguin amplitudes.
It is know that the CP asymmetry for B→ψKs and B→Ksψ have equal CP asymmetry in the standard model. Experiments have given strong hints that these CP violations are not equal. It has been shown that it is impossible to understand the experimental results within the frame work of Super Symmetric theories.
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