关于手征对称性自发破缺和强子质量的研究

In this project we plan to study the spontaneously chiral symmetry breaking and the chiral structure of hadrons, which are important to understand the low energ behavior of QCD. We use the method of QCD sum rule as well as an algebraic method proposed by S. Weinberg: using chiral transformation equations to study the chiral structure of hadron interpolating fields, then study the chiral structure of hadrons, and finally calculate the mass and decay properties of hadrons. We also use the method of the extended chiral SU(3) quark model to study the hadron interactions. There are four subjects: study on the chiral structure of baryon interpolating fields and calculate their masses and axial coupling constants; study on the non-local baryon fields and the pentaquark interpolating fields as the higher order corrections of conventional baryons; study on the chiral structure of tetraquark and hexaquark interpolating fields; study on the interactions of hadron states. We hope that we can furtherly understand the low energy behaviors of QCD, especially, the internal structure of proton and neutron and their interactions. We also hope that these studies can give us a new viewpoint to understand the proton spin and the nuclear force, etc.

手征对称性的自发破缺和强子的手征性质是国际上很重要的研究课题。我们计划使用QCD求和规则的方法和S. Weinberg提出的代数学的方法：通过计算手征变换方程来研究强子场的手征性质，从而推导出强子态的手征性质，最后计算强子态的质量和衰变等物理量。我们还计划使用手征夸克模型研究强子态之间的相互作用。具体有以下四个研究方面：由重子场的手征性质出发研究重子的质量和轴矢耦合常数等物理量；研究非局域重子场和五夸克重子场等的手征性质，做为三夸克局域重子场的高阶修正；研究四夸克介子态和六夸克介子态的手征性质；研究强子态之间的相互作用。通过这些研究，一方面有望更深入地理解QCD在低能时的非微扰性质，以及重子特别是质子和中子的内部结构、相关性质和它们之间的相互作用方式，另一方面将对质子自旋和核力的相关性质等重要科学问题从新的角度给出新的思路。

项目组成员围绕奇特强子态和重味强子态开展理论研究工作，通过系统分析它们各种可能的内部结构，改进了QCD求和规则方法，使之更适用于开展强子谱的计算。应用此方法研究了Pc(4380)等十余个奇特强子态和一系列单重强子态的质量谱和衰变等性质，为相关理论和实验研究提供了重要参考。发表SCI论文25篇，其中第一/通讯作者论文24篇，含1篇Physics Reports、1篇Reports on Progress in Physics、1篇PRL、15篇PRD等。