胶球的格点QCD研究

The Study of Glueball in Lattice QCD

胶球是强子物理的重要研究对象,也是我国北京谱仪(BESⅢ)实验寻找的重要物理目标。格点量子色动力学作为从第一性原理出发的研究强相互作用非微扰特性的方法,是研究胶球问题的重要理论工具。本工作介绍了近年来格点量子色动力学理论对胶球性质的一些研究进展,并讨论实验上发现的若干共振态作为胶球的可能性。另外,规范场拓扑荷密度在纯规范理论中可以作为内插场算符来研究赝标量胶球性质,但在具有u,d,s动力学海夸克组态上的拓扑荷密度算符的关联函数中,只观察到轻赝标量介子η和η’的贡献。这启示我们在具有动力学海夸克的情形下,需要构造多种形式的内插场算符来研究赝标量胶球。

The study of glueballs is an important topic in hadron physics,and the search for glueball states is one of the major goal of the Beijing Spectrometer III(BESIII)experiment.Lattice quantum chromodynamics,as a first-principle approach to examine the non-perturbative characteristics of the strong interaction,is an essential theoretical tool to investigate the glueball problem.Recent development of lattice studies on glueballs and possible experimental candidates are reviewed in this article.In addition,the topological charge density of the gauge field can be used as an interpolation field operator to study the properties of pure-gauge pseudoscalar glueball,but only the contributions of the light pseudoscalar mesonsηandη′are observed in the correlation function of topological charge density operator on gauge configurations with dynamical sea quarks u,d and s.Our result implies that,in the presence of dynamical sea quarks,one needs to construct more different types of operators to study the pseudoscalar glueball.