Chiral symmetry on the light-cone and effective models

光锥的手性对称性和有效模型

基本信息

批准号：
15540288
负责人：
YAZAKI Koichi
金额：
$ 1.54万
依托单位：
Tokyo Woman's Christian University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2006
项目状态：
已结题

项目摘要

This project followed the previous one "Models of hadrons on the light-cone" (project no.11640258) supported by the Grant-in-Aid for Scientific Research (Basic Research (C) (2)) for the period 1999-2002, and aimed at clarifying how to describe the spontaneous breakdown of chiral symmetry, which is related to the structure of vacuum in the conventional formulation of field theory, in the light-cone formulation, where the vacuum is known to be trivial, and how it is reflected in effective models.In the conventional formulation, the Nambu-Goldstone (NG) particle, which appears as a result of the symmetry brealing, is generated by a local soft modulation of the symmetry transformation generator, and therefore the connection to the underlying symmetry is transparent. This was not the case in the light-cone formulation. We have clarified the connection by considering the peculiar kinematics of the light-cone coordinate and introducing a non-local modulation of the symmetry operator. Actual construction of the modulated operator was made for the Nambu-Jona-Lasinio (NJL) model, which is considered to be an effective theory of QCD. This work has been published in Physical Review D.Concerning effective models, I have continued the collaboration and used the quark-diquark model, which was derived from a relativistic Faddeev approach to 3-quark system in the NJL model, to study the effect of nuclear medium on the structure functions of the nucleon. The calculation gave a reasonable description of the experimentally observed EMC effect. This work has been published in Nuclear Physics A.

该项目遵循了先前的“轻锥上的hadron的模型”（项目编号11640258），并在1999-2002期间得到了科学研究赠款（基础研究（C）（2））的支持。并旨在澄清如何描述手性对称性的自发分解，这与在野外理论的常规表述中的真空结构相关，在轻锥公式中，该表态被已知真空及其是如何的，以及它是如何的反映在有效模型中。在常规配方中，由对称性布莱尔（Brealing）产生的Nambu-goldstone（NG）粒子是由对称性转化发生器的局部软调制而产生的，因此与基础对称性的连接有关是透明的。在轻锥公式中并非如此。我们通过考虑光锥坐标的特殊运动学并引入对称操作员的非本地调制来阐明这种联系。对Nambu-Jona-Lasinio（NJL）模型进行了调制操作员的实际结构，该模型被认为是QCD的有效理论。这项工作已发表在物理审查中d。关注有效的模型，我继续进行了协作，并使用了Quark-Diquark模型，该模型源自NJL模型中的3 Quark System的相对论FADDEEV方法，以研究NJL模型的3 Quark System核培养基的结构功能。计算给出了实验观察到的EMC效应的合理描述。这项工作已发表在核物理A中。