关键词: 
3π /
奇特态 /
重子谱 /
三级级联衰变 /
分波分析

摘要: 在强子物理研究中，3π产生的理论和实验有非常重要的意义，是目前世界上很多大型实验设备的重要研究对象。3π强子物理包含丰富的物理内容，可以作为探索低能区强相互作用的有力工具。同时，3π产生过程是寻找奇特轻介子态的主要途径之一。另外，通过研究3π产生反应道还可以寻找“失踪”共振态和重子激发态之间的级联衰变。介绍了目前国际各大高能物理实验室的3π产生过程的实验、理论研究以及分波分析技术现状，重点介绍了美国杰弗逊国家实验室（Jefferson Lab，简称JLab）的CLAS（CEBAF Large Acceptance Spectrometer）实验上的3π反应过程。最后，指出了3π强子物理研究的意义和未来的研究方向。Three pion productions off nucleon are of significance in the research of hadron physics. Meanwhile it is the subject of many big experimental apparatus in the world. Due to the variety of three pion productions, it can be applied as an effective tool to study QCD in low energy region. Three pion productions is one of the main reactions in searching light exotic meson state. Moreover, it is possible to find out the "missing" baryon resonance and the cascaded decay process between baryon excited states. We introduce present experiments and theories of three pion productions as well as the partial wave analysis technique. The emphasis is on the CLAS (CEBAF Large Acceptance Spectrometer) experiment at JLab (Jefferson Lab). In the end, we point out the significance of studying the three-pion hadron physics at JLab.