Quantum Chromodynamics and Low Energy Effective Theory with Skyrmion.

作为量子色动力学(QCD)的低能有效理论，我们研究了作为非线性Sigma模型的孤子解的Skyrmions。我们还研究了手征孤子模型和非相对论夸克模型之间的关系。非相对论夸克模型对QCD的建立起着重要的作用，并且很好地重现了实验数据。本文的主要研究成果如下：1.通过引入自旋-同位旋转动和呼吸运动，研究了三维球面上量子化手征孤子的拓扑性质。在Skyrmion图像的基础上，是否一致地描述包含高阶修正的π-核子散射一直是一个悬而未决的问题。这个项目解决了问题的要害。通过改变QCD的颜色自由度NC，研究了手征孤子模型和非相对论夸克模型中的自旋-反转重子-顶点。已经开始了一种考虑夸克自由度的方法，而在手征孤子模型中没有考虑到这一点。

We have studied skyrmions which are soliton solutions of nonlinear sigma model as the low energy effective theory of the quantum chromodynamics (QCD). We also investigate relations between the chiral soliton model and the nonrelativistic quark model which plays important role to establish QCD and well reproduces the experimental data phenomenologically. Our main results of this research project are as follows :1. Topological properties of quantized chiral soliton on the 3-dimensional sphere are studied by introducing spin-isospin rotations and the breathing motion.2. On the basis of the skyrmion picture whether a consistent description of the pion-nucleon scatterings including higher order corrections has been a long-pending problem. Essential point of the problem is solved by this project.3. By changing the color degree of freedom N_C of QCD we studied the spin-flip baryon-vertex in the chiral soliton model as well as in the nonrelativistic quark model.4. An approach has started that takes into account of the quark degree of freedom which is not considered in the chiral soliton model.