Roles of Instantons in the Low Energy QCD

点击翻译按钮获取中文摘要

This research aims at the study of properties and effects of the instanton induced interaction, which comes from te coupling of light quarks to the QCD instanton solution. We pointed out that the instanton induced interaction has a distinctive color-flavor structure and thus shws a different spin-flavor dependences from the perturbatve gluon exchange nteraction. We proposd that a part of the gluon exchange force in the baryon spectrum is in fact the instanton induced interaction and then some of the difficulties that the quark model fces can be solved.This interaction gives a distinctive features in the baryon-baryn interactions at short distances. According to the quark cluster model calculation, the instanton induced interaction yields a new attractive force between two nuceons. Furthermore, the H dibaryon system receives a strong repulsion due to the three-body part of the instanton induced interaction. We conclude that the H dibaryon may not show as a deep bound state below the two lambda threshould. We studied the effects of the instanton indeuced interaction in other dibaryon systems.The P-wave baryon spectrum, the spin-orbit force is weak in the nonstrange system, while it gives fair splittings in the strange sector. The short distance NN interactin also requires a strong spin-orbit force among quarks. We pointed out that the spin-orbit force has two origins, the instanton induced interaction and the gluon exchange, which brings the various spin-orbit structures.