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CP Violation in Physics

物理学中的 CP 违反

基本信息

批准号：
09246103
负责人：
SANDA Ichiro
金额：
$ 27.26万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research on Priority Areas (A)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09246103/
关键词：
B-Physics aerogel PID R+D CSI Particle identification B meson ロアロゲルエアロゲル

项目摘要

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>.

为了了解我们宇宙的起源，我们绝对有必要了解CP违背的起源。为此，KEK建造了一个能产生大量B介子的加速器。目标是检测由Kobayashi Maskawa模型预测的大CP违逆。在SLAC也开始了类似的项目。这个项目的目标之一是首先发现大的CP违背。理论小组的目标是通过预测在哪里可以找到进一步的CP违反来支持实验小组。在2001年物理年，Belle宣布在B衰变中发现了大CP违逆：sin 2φ_1 = 0.99±0.14（stat）±0.06（syst）。从统计学上讲，这一结果表明在B→J/ψKs衰变中不存在CP破坏的概率小于1 / 10^7。在2001年7月的高能轻子光子相互作用国际会议上，这一结果与SLAC的类似结果同时公布。2001年2月19日至12日在伊势举行的B物理和CP违反国际研讨会上公布了初步结果。这次会议是由这笔拨款赞助的。理论组研究了在B→Kπ、π^+π^-、π^+π^0、K^+K^-、K^+K^0中观测CP违逆的可能性。该小组的另一个发现是首次观察到改变风味的中性电流相互作用，B→X_3l^+l^-。Br (B→Kμμ^ + ^ -)= (0.99 ^ ^ < + 0.39 + 0.13 > __ < -0.32 > -0.15)x 10 ^ < -15 >。