Experimental study of particle physics in TeV region at LHC

标准模型用希格斯机制解释了粒子质量的起源。标量粒子的自相互作用导致真空的自发对称性破缺。一种叫做希格斯粒子的标量粒子是一种物理上可以观察到的粒子。它的质量预计小于约1TeV，超对称粒子也有望出现在这个能区。欧洲核子研究中心(CERN)的大型强子对撞机(LHC)项目于1994年12月正式获批，计划于2005年投入使用。LHC是一台质子-质子对撞机，束流能量为7TeV，大约比目前最高的机器能量高一个数量级。阿特拉斯实验是利用这台机器研究1TeV能区的通用探测器。我们一直在与来自33个国家的物理学家合作进行阿特拉斯探测器的研究和开发。我们已经完成了以下五项工作：(1)Muon探测器和触发系统，(2)硅探测器，(3)超导螺线管，(4)高速数据采集系统，(5)物理分析软件。至于Muon探测器和触发系统，我们提交了详细的技术设计报告(TDR)。我们完全负责建造磁场为2特斯拉的超导螺线管。提交了一份详细的TDR，螺线管现在正在建造中。对于触发系统和高速数据采集系统，我们已经做了详细的设计，并正在筹备TDR；软件方面，我们开发了基于面向对象技术的软件工具。我们特别关注了“GEANT4”，一个详细的探测器模拟程序包。在ATLAS合作的整个研究和发展过程中，与合作者的密切联系和密集讨论是必不可少的。只有使用助学金才有可能进行富有成效的研究。

Standard model explains the origin of particle masses with the Higgs mechanism. Self interaction of scalar particles result in a spontaneous symmetry breaking of the vacuum. One scalar particle, called Higgs particle, is a physically observable particle. Its mass is expected to be less than approximately 1 TeV.Supersymmetric particles are also expected to be in this energy region. Large Hadron Collider (LHC) project at CERN was officially approved in December 1994, and is scheduled to be operational in 2005. LHC is a proton-proton collider with the beam energy of 7 TeV,approximately one order of magnitude higher than the present highest machine energy. ATLAS experiment is a general purpose detector to study the 1 TeV energy region using this machine.We have been doing research and development for the ATLAs detector in collaboration with physicists from 33 countries. We have been contributing to the following five items : (1) Muon detector and trigger system, (2) Silicon detector, (3) Superconducting solenoid, (4) High-speed data acquisition sytem, and (5) Software for physics analysis. As for the muon detector and trigger system, we submitted a detailed technical design report (TDR). We are totally responsible for the construction of the superconducting solenoid with 2 tesla of a mgnetic field. A detailed TDR was submitted, and the solenoid is now under construction. As for the trigger system and the high-speed data acquisition system, we have done detailed design, and are preparing for a TDR.As for the software, we developed software tools based on object oriented technology. We especially concentrated on "GEANT4", a detailed detector simulation package. Throughout the research and developments in the ATLAS collaboration, close contact and dense discussions with collaborators are essential. It was only possible to make fruitful research with using the grant-in-aid.