Study of CP violation in B-meson decays

百丽硅顶点探测器(SVD)是在该基金和其他基金的支持下协同工作成功建造和组装的。在贝利探测器上安装了奇异值分解后，进行了贝利实验。该探测器已经达到了预期的性能，为贝尔实验提供了最有价值的实验信息，特别是关于B介子衰变顶点位置的实验信息。这使得我们能够测量B介子衰变的CP破坏参数。另一方面，人们注意到对低动量粒子的跟踪效率需要提高。这可以通过在现有的SVD的基础上增加两层硅探测器来实现。我们正在设计升级后的SVD，我们计划很快开始研发工作，以便升级后的SVD可以在2002年夏天安装。至于物理活动，我们可以第一次观察到B介子衰变到φK态。这就是可以通过所谓的“企鹅图”进行的过程。因此，它将为研究这一图表提供一个独特的场所。

Belle silicon vertex detector (SVD) was successfully built and assembled by the collaborative work supported by this fund and also other funds. The Belle experiment has been carried out after installing SVD in the Belle detector. This detector has been working with the expected performance and it has provided most valuable experimental information of the Belle experiment, especially on the decay vertex position of B-mesons. This enables us to measure the CP violation parameter of the B-meson decays.On the other hand, it has become noticed that the tracking efficiency for low momentum particles need to be improved. This can be made by having two more layers of the silicon detector to what we have for the present SVD.We are designing the upgraded SVD and we plan to start R＆D works soon so that the upgraded SVD can be ready for installation in the summer 2002.As for the physics activities, we could observe the B-meson decay into φK state for the first time. This is the process which can proceed through the so-called "Penguin diagram". Therefore it will provide a unique place for studying this diagram.