Search for New Particles and Study of Interactions between Particles with "OPAL" Detector at Electron Position Collider "LEP".

在电子位置对撞机“LEP”上使用“OPAL”探测器寻找新粒子并研究粒子之间的相互作用。

基本信息

批准号：
01044047
负责人：
MINOWA Makoto
金额：
$ 16.96万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1991
项目状态：
已结题

项目摘要

The OPAL experiment, in which we are participating, is one of the four experiments at the large electron-positron collider at CERN (LEP) which started operation in August 1989 to study electron-positron reactions in the vicinity of the Z^0 resonance. We successfully recorded 30k Z^0 events in 1989, which led to numerous exciting findings from the beginning of the experiment. In the following years more and more Z^0 events (170k events in 1990 and 400k events in 1991) were collected to obtain yet more precise and significant results. Among the most important findings we have obtained are :1. Precise determinations of Z^0 properties (mass, total width, partial widths, etc.) which verified the validity of the standard model.2. There are only 3 generations of the elementary particles. This significantly constrained various models of the origin of the universe.3. The Higgs particle, elementary scalar particle essential in the standard model, is heavier than 51 GeV.4. The mass of the top quark, the sixth quaxk in the standard model, probably lies between 100 GeV and 180 GeV.5. No new particles, such as supersymmetric (SUSY) partners, exists up to the Zo energy region.6. Precise determination of the properties of the tau leptons and the bottom quarks, which were abundantly observed as decay products of the Z^0 particle. These data further signify the validity of the standard model.7. The coupling constant of the strong interaction was precisely determined. The theory of the Quantum Chromodynamics (QCD) was extensively examined in various ways.8. Grand Unified Theories were examined. The simplest SU (5) model proved not in accordance with our data, instead the SUSY SU (5) model looks most promising.As LEP keeps running at the Z^0 resonance, several millions of Z^0 events will be collected by the end of 1993, which will enable us to look for possible breakings of the standard model.

我们参与的蛋白石实验是Cern（LEP）大型电子峰值对撞机的四个实验之一，该实验于1989年8月开始运行，研究了Z^0共振附近的电子 - 旋律反应。我们在1989年成功记录了30k Z^0事件，从实验开始就导致了许多令人兴奋的发现。在接下来的几年中，收集了越来越多的Z^0事件（1990年的170K事件和1991年的400K事件），以获得更精确和更重要的结果。我们获得的最重要的发现之一是：1。 Z^0属性（质量，总宽度，部分宽度等）的精确确定，该属性验证了标准模型的有效性2。只有3代基本粒子。这显着限制了宇宙起源的各种模型3。标准模型中必不可少的基本标量粒子的希格斯粒子比51 GEV.4重。标准模型中的第六个Quaxk的顶部夸克的质量可能位于100 GEV至180 GEV之间。5。没有新颗粒，例如超对称（SUSY）伙伴，都存在于ZO能量区域。6。精确测定tau lept子和底部夸克的性质，这些特性被大量地观察到Z^0粒子的衰减产物。这些数据进一步表示标准模型的有效性7。精确确定了强相互作用的耦合常数。量子染色体动力学（QCD）的理论以各种方式进行了广泛的研究。8。研究了大统一理论。最简单的SU（5）模型证明不符合我们的数据，而是Susy Su（5）模型看起来最有前途。随着LEP保持在Z^0共振，将在1993年底之前收集数百万个Z^0事件，这将使我们能够寻求标准模型的可能中断。