| Project/Area Number |
13304016
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (A)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
素粒子・核・宇宙線
|
|---|
| Research Institution | The University of Tokyo |
|---|
Principal Investigator |
AIHARA Hiroaki The University of Tokyo, Graduate School of Science, Professor, 大学院・理学系研究科, 教授 (60167773)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
IWASAKI Masako International Center for Elementary Particle Physics, Research Associate, 素粒子物理国際研究センター, 助手 (70345172)
田島 宏康 東京大学, 素粒子物理国際研究センター, 助手 (80222107)
|
|---|
| Project Period (FY) |
2001 – 2003
|
| Project Status |
Completed (Fiscal Year 2003)
|
| Budget Amount *help |
¥53,170,000 (Direct Cost: ¥40,900,000、Indirect Cost: ¥12,270,000)
Fiscal Year 2003: ¥9,490,000 (Direct Cost: ¥7,300,000、Indirect Cost: ¥2,190,000)
Fiscal Year 2002: ¥18,200,000 (Direct Cost: ¥14,000,000、Indirect Cost: ¥4,200,000)
Fiscal Year 2001: ¥25,480,000 (Direct Cost: ¥19,600,000、Indirect Cost: ¥5,880,000)
|
|---|
| Keywords | Elementary particles / Particle accelerator / CP violation / Symmetry / Solid state detectors / B meson / the Standard Model / Supersymmetry |
|---|
| Research Abstract |
1)We have searched for physics beyond the Standard Model based on precision measurements of CP violation in B meson system. The B to phi Ks decay is induced by a quantum loop (a.k.a. penguin) process, where New Physics can contribute. CP asymmetry measured in B to phi Ks, therefore, can be different from that in B to J/psi Ks, where only the tree Standard Model process dominates. Based on 152 million B anti-B pairs observed by Belle detector, we have determined CP asymmetry for B to phi Ks to be S=-0.96+-0.52, which is somewhat disagreement with CP asymmetry for B to J/psi Ks, S=+0.733+-0.057+-0.028. We must further improve the statistical accuracy of this measurement to see if this potential discrepancy remains true.
2)We have observed large CP violation in B to pi+pi- decay using 152B anti-B pairs, for the first time.
3)We have measured, for the first time, the inclusive branching faction of Flavor Changing Neutral Currents process, b to s l+l-, where l can be an electron or a muon. We determined Br(b to sl+l-) to be (4.39+-0.84+0.78-0.73) x 10-6. This measurement can be used to constrain many New Physics models including Supersymmetric model.
|
