手征微扰理论与强子物理

Quantum Chromodynamics (QCD) is the underlying theory of strong interaction, which has three fundamental features: asymptotic freedom, color confinement, and approximate chiral symmetry and its spotaneous breaking. As an effective field theory of QCD, Chiral Perturbation Theory is widely used in hadron physics. Within this framework, the mass or four-momentum of the pseudoscalar meson is treated as the small parameter of the chiral expansion. Our group plans to investigate the chiral corrections to the magnetic moment, radiative decay width and semi-leptonic decay process of the heavy flavored baryons. Moreover we will explore the chiral dynamics of the low-lying scalar mesons below 1 GeV in order to distinguish whether they are candidates of molecular states or tetraquark states.

量子色动力学是描写夸克胶子之间强相互作用的基本理论,它具有三个很基本的性质: 渐近自由、色禁闭、手征对称性及其自发破缺。手征微扰理论把QCD的色禁闭与手征对称性的自发破缺作为实验事实接受下来作为出发点, 把赝标介子质量或四动量作为微扰展开的小参量,在非微扰的低能强相互作用领域应用广泛. 本申请书拟利用手征微扰理论来讨论重味重子体系的磁矩, 电磁衰变和半轻衰变过程. 针对轻标量介子系统, 拟利用手征微扰理论来探讨在分子态或四夸克态假定下, 轻标量粒子的质量,总宽度等物理量以及电磁衰变过程的手征动力学和它们随流夸克质量的不同依赖关系, 希望结合格点QCD对轻标量粒子的数值模拟来区分分子态或四夸克态这两种不同的物理图像.

量子色动力学是描写夸克胶子之间强相互作用的基本理论,它具有三个很基本的性质: 渐近自由、色禁闭、手征对称性及其自发破缺。手征微扰理论把QCD的色禁闭与手征对称性的自发破缺作为实验事实接受下来作为出发点, 把赝标介子质量或四动量作为微扰展开的小参量,在非微扰的低能强相互作用领域应用广泛. 在基金项目的资助下, 我们课题组利用手征微扰理论, 非常系统地讨论重味重子体系的磁矩和电磁衰变, 两个物质场之间的强相互作用.