Theoretical Study of Particles and Fields

这个项目的主要目的是了解自然界的基本组成及其性质，以及粒子物理的基本理论框架。为此，藤川和山田一起研究了夸克的手性结构，特别是顶夸克。根据电子-正电子湮没的实验数据，证明了顶夸克的手征结构是相当准确的。受这一分析的启发，藤川还研究了夸克和轻子的模型及其手征结构。江口和他的合作者阐明了与超对称规范理论动力学有关的基本问题。清楚地分析了有无物质的超对称Yang-Mills理论的共形性质。此外，通过结合弦理论的观点，阐明了4维以及3维和5维时空中的一些场论性质。他还研究了与弦理论和量子引力有关的几个基本问题。柳田和他的合作者研究了标准模型的超对称扩展的各个方面。特别是对大统一方案中的等级问题进行了分析。他提出了一个可能的方案，最终可能解决为什么在当前能量下的物理和在大统一尺度上的物理可以统一在一个自然的理论框架中，而不会引起大的质子衰变。他还分析了超对称破缺机制的基本问题。应该强调的是，来自欧洲核子研究中心的来访者为我们的理论小组提供了极具刺激性的信息。

The major purpose of this project is to understand the basic constituents of the Nature and their properties, together with the basic theoretical framework of particle physics.For this purpose, Fujikawa together with Yamada studied the chiral structure of quarks, in particular, the top quark. On the basis of the experimental data from electron-positron annihilation, it has been shown that the chiral structure of the top quark holds quite accurately. Motivated by this analysis, Fujikawa also studied a model of quarks and leptons and their chiral structure.T.Eguchi together with his collaborators clarified the basic issues related to the dynamics of supersymmetric gauge theories. The conformal properties of supersymmetric Yang-Mills thoeries with or without matters have been clearly analyzed. Also, some of field theoretical properties in 4 as well as 3 and 5 dimensional space-time have been clarified by incorporating the string theoretical view point. He also studied several fundamental issues related to string theory and quantum gravity.T.Yanagida together with his collaborators studied various aspects of super-symmetric extension of the standard model. In particular, he made an analyis related to the issue of the hierarchy problem in the grand unification scheme. He put forward a possible scheme which may eventually solve why the physics at the present energies and the physics at the grand unification scale can be unified in a natural theoretical framework, without inducing large proton decay. He also analyzed the basic issue of supersymmetry breaking mechanism.It should be emphasized that the visitors from CERN provided extremely stimulative information to our theory group.