量子场论的新形式  

New formalism of quantum field theory

作　　者：冯波 Bo Feng(Zhejiang Institute of Modern Physics,Department of Physics,Zhejiang University,Hangzhou 310027,China)

机构地区：[1]浙江大学物理系近代物理中心,杭州310027

出　　处：《科学通报》2018年第24期2530-2535,共6页Chinese Science Bulletin

摘　　要：近年来,Large Hadron Collider(LHC)等高能加速器的运行,使实验的精度大大提高,因此对理论上计算散射振幅提出了严峻的考验.传统的费曼图技术,特别是涉及规范粒子的相互作用时,由于费曼图增加的速度、表达式的复杂度、不有效性等,无法应对这些新的挑战.为了解决这个问题,理论学家们开展了各方面的研究.通过过去十多年的探索,取得了许多重大的进展,包括树图振幅的在壳递推关系,无质量粒子散射振幅计算的Cachazo-He-Yuan(CHY)框架,场论中散射振幅几何描述的Grassmannian框架和Amplituhedron框架等等.这些新的计算方法,能快速精确地计算树图以及圈图的修正,更好地分析标准模型的背景贡献和新物理信号的提取.从而能很好地和实验数据对比,完美地应对了当前实验的挑战.上面这些理论方案的突破,都有些共同特点.这些共同特点,特别是许多计算框架的在壳性,暗示了区别于传统的、基于拉格朗日框架下的、量子场论新表述形式存在的可能性.本文就此进行了一些讨论和展望.In recent years, theoretical calculations of scattering amplitudes face a huge challenge because experiment data coming from colliders, such as Large Hadron Collider （LHC）, become more and more accurate. The traditional Feynman diagram technique can not deal with the problem because the difficulties involving gauge interaction. To solve the problem, theo- rists have made many studies. Through investigations of last fourteen years, we have achieved many important progress- es, such as on-shell recursion relation, the Cachazo-He-Yuan framework for scattering amplitudes of massless particles, the geometric Grassmannian and Amplituhedron frameworks for N=4 SYM planar amplitudes, etc. These new methods can calculate tree-level and loop scattering amplitudes much faster than the traditional method, so have improved our ability to analyze background contributions from Standard Model and find possible signals of new physics by comparing with experiment data. These breakthroughs have some common features. These features, such as the focus of on-shell properties, the right choice of prescription variables and the emphasize of the analytic properties of scattering amplitudes, hint a possible new formalism of quantum field theory, which is very different from traditional Lagrangian formalism. In this article, we give a brief discussion of this topic.

关 键 词：量子场论 新形式 散射振幅 

分 类 号：O413[理学—理论物理]