2001 Fiscal Year Final Research Report Summary
| Project/Area Number |
09246103
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research on Priority Areas (A)
|
| Allocation Type | Single-year Grants |
|---|
| Research Institution | Nagoya University |
|---|
Principal Investigator |
SANDA Ichiro Nagoya University, Granduate School of Science, Professor, 大学院・理学研究科, 教授 (60242806)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
KOBAYASHI Makoto High Energy Accelerator Reserch Organization, Professor, 素粒子原子核研究所, 教授 (90025453)
OHSHIMA Takayoshi Nagoya University, Granduate School of Science, Professor, 大学院・理学研究科, 教授 (00134651)
AIHARA Hiroaki Tokyo University, Graduate School of Science, Assistant Professor, 大学院・理学系研究科, 助教授 (60167773)
YOSHIMURA Motohiko Tohoku University, Graduate School of Science, Professor, 大学院・理学研究科, 教授 (70108447)
MASKAWA Toshihide Kyoto University, Department of science, Professor, 基礎物理学研究所, 教授 (60022612)
|
|---|
| Project Period (FY) |
1997 – 2001
|
| Keywords | B-Physics / aerogel / PID R+D / CSI / Particle identification / B meson |
|---|
| Research Abstract |
To understand the origin of our universe, it is absolutely necessary for us to understand the origin of CP violation. To this end KEK has built an accelerator which produces large number of B mesons. The goal was t detect the large CP violation predicted by the Kobayashi Maskawa model. Similar project was started at SLAC. One of the goal of this project was to discover the large CP violation first. The goal of the theory group was to support the experimental group by making predictions as to where further CP violation can be found.
During the physical year of 2001, Belle announced the discovery of large CP violation in B decay : sin 2φ_1 = 0.99 ± 0.14(stat) ± 0.06(syst). Statistically, this result implies that there is less than 1 part in 10^7 that CP violation is absent in B → J/ψKs decay. This result was announced simultaneously with similar SLAC result at the international Conference in Lepton Photon Interactions at High Energies in July, 2001. A preliminary result was announced at International Workshop on B Physics and CP Violation, held at Ise during the period of Feb. 19-12, 2001. This conference was sponsored by this grant. The theory group studied possibilities of observing CP violation in B → Kπ,π^+π^-, π^+π^0, K^+K^-, K^+K^0. Another discovery made by this group is the first oservation of flavor changing neutral current interaction, B → X_3l^+l^-. Br(B → Kμ^+μ^-) = (0.99^^<+0.39 +0.13>__<-0.32 -0.15>) x 10^<-15>.
|
