B-MESON PHYSICS BY ELECTRON-POSITRON COLLISIONS

电子-正电子碰撞的 B-介子物理

• 批准号: 05302018
• 负责人: FUJIWARA Noboru
• 金额: $ 12.22万
• 依托单位: NARA WOMEN'S UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Co-operative Research (A)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-05302018/
• 关键词: Standard model; Kobayashi-Maskawa model; CP violation; B factory; B meson; b-quark

The final physics objective of this study is to measure the CP violation via B meson decays. In order to achieve that, we must realize a B-factory which produce a large number of B meson decays by asymmetric-energy electron-position collider. We started this study as basic and realistic preparation of the B-factory in Japan. Fortunately, the B-factory project at KEK was approved in 1994, we could make systematic and thorough activities for the construction of B-factory in these three years. The main results are summarized as follows.(1) The first yearWe have organized the world-wide experimental team, named as 'BELLE collaboration', based on the collaboration of this Grant-in-Aid for Co-operative Research (A). We then could complete a Proposal for B-factory Experiment, as a 'Letter of Intent.'. The first design baseline is that the BELLE detector would be constructed at Fuji experimental hall, using VENUS super-conducting magnet and support structure.(2) The second yearThe design of the accelerator was changed, especially, the interaction region was moved to Tukuba experimental hall. Therefore, the design for BELLE detector was drastically changed, e.g., new magnet, new support structure, new shape of vertex detector etc. We have completed a detailed 'Technical Design Report' in this year.(3) The third yearMost of the specifications had been fixed by this year except for Particle Identifier (PID). After long term of dedicated efforts, we have selected a Aerogel Cherenkov counter and TOF as the baseline for PID.Since all the specifications were fixed, we can start the detector integration from next year. As a whole, we could achieve the major part of the preparation for the construction of the B factory as expected.

本研究的最终物理目标是通过B介子衰变测量CP破坏。为了实现这一目标，我们必须在非对称能量电子位置对撞机上实现产生大量B介子衰变的B工厂。我们开始这项研究作为基本的和现实的准备在日本的B工厂。幸运的是，KEK的B工厂项目于1994年获得批准，我们可以在这三年内为B工厂的建设进行系统而深入的活动。主要研究结果如下。(1)第一年我们在合作研究补助金（A）的基础上，组织了一个世界范围的实验团队，命名为“贝儿合作”。然后，我们可以完成一个B工厂实验的提案，作为一个“意向书”。'.第一个设计基准是贝儿探测器将在富士实验大厅建造，使用金星超导磁体和支撑结构。(2)第二年，加速器的设计发生了变化，特别是相互作用区被移到了土库巴实验大厅。因此，贝儿检测器的设计发生了重大变化，例如，新的磁铁，新的支撑结构，新形状的顶点探测器等，我们已经完成了详细的'技术设计报告'在今年。(3)第三年除了粒子识别器（PID）外，大部分的规格都在这一年得到了固定。经过长期的努力，我们选择了气凝胶切伦科夫计数器和TOF作为PID的基线。由于所有规格都已确定，我们可以从明年开始进行探测器集成。整体而言，我们能够如期完成B工厂建设的主要准备工作。

项目成果

S.Okuno et al.: "A stacked dielectric film for a silicon microstrip detector" Nuclear Instruments & Methods. A361. 91-96 (1995)

S.Okuno 等人：“用于硅微带探测器的堆叠介电薄膜” Nuclear Instruments

Belle Collaboration: "Letter of Intent for A Study of CP Violation in B Meson Decays" KEK Report. 94-2. 1-199 (1994)

Belle 合作：“B 介子衰变中 CP 破坏研究的意向书”KEK 报告。

M.Tanaka et al.: "LSI design and data-acquisition architechture for a silicon micro-vertex detector at the KEK B-factory" Nuclear Instruments & Methods. A342. 149-155 (1994)

M.Tanaka 等人：“KEK B 工厂硅微顶点探测器的 LSI 设计和数据采集架构” Nuclear Instruments

Adachi et al.: "Study of a threshold Cherenkov counter based on silica aerogels with low refractive indices" Nuclear Instruments & Methods. A355. 390-398 (1995)

Adachi 等人：“基于低折射率二氧化硅气凝胶的阈值切伦科夫计数器的研究” Nuclear Instruments

M.Tanake et al.: "Readout system of the silicon microstrip vertex detector of the KEK B-Factory" Nuclear Instruments & Methods. A342. 169-174 (1994)

M.Tanake 等人：“KEK B-Factory 硅微带顶点探测器的读出系统” Nuclear Instruments