Study of chiral symmetry and internal structure of the nucleon

本研究的目的是扩展我们以前在NJL模型基础上对核子内部结构的研究，通过计算结构函数来检验模型的动力学性质，并研究核子内部结构在核介质中的变化。由于光锥公式是最方便的计算结构函数，我们已经开发的NJL模型的光锥哈密顿形式主义。光锥上费米子的一个特征是其动力学分量的数量变为通常公式的一半，并且在存在相互作用的情况下消除非动力学分量并非微不足道。我们引入了对应于标量和赝标介子的辅助场来处理这个问题。然后用1/N展开法求解辅助场的约束方程，得到最低阶的差距方程和次阶的哈密顿量中的相互作用项。皮欧 ...更多信息 n由夸克-反夸克系统的Tamm-Dancoff方程描述，本征函数与π介子结构函数直接相关。我们考虑了两种正则化方法来处理差距方程和π介子本征值方程中的发散积分。一个是Lepage和Brodsky提出的方案的扩展版本，几乎等价于常规公式中的正则化。另一种是由伦茨，Ohta，Thies和Yazaki提出的，只对横向进行正则化，而对纵向进行重正化，其方法类似于二维世界中的Gross-Neveu模型。后者已被发现给更好的结果的π结构函数。预计这种形式主义将是一个更一般的框架来描述光锥上的手征对称性的一步。相对论Faddeev方法中的核子结构函数也是用光锥变量计算的，虽然我们还没有发展出这种情况下的光锥哈密顿形式.此外，我们还用相对论谐振子夸克模型研究了核子在核介质中传播的内部动力学，并与色透明问题联系起来.我们还研究了H-重子之间的相互作用，以探讨多奇异重子物质的可能性。少

The purpose of this research is to extend our previous research on the internal structure of the nucleon based on the NJL model, examine the dynamical aspects of the model by calculating the structure function and study the change of the nucleon internal structure in nuclear medium. Since the light-cone formulation is the most convenient for calculating structure functions, we have developed the light-cone hamiltonian formalism of the NJL model. A characteristic feature of fermions on the light-cone is that the number of their dynamical components becomes half of the usual formulation and the elimination of the non-dynamical components in the presence of interactions is not trivial. We have introduced auxiliary fields corresponding to scalar and pseudo-scalar mesons to treat this problem. The constraint equations for the auxiliary fields are then solved with 1/N expansion, giving the gap equation in the lowest order and the interaction term in the hamiltonian in the next order. The pio … More n in this scheme is described by the Tamm-Dancoff equation for quark-antiquark system and the eigenfunction is directly related to the pion structure function. We have considered two regularization schemes to treat divergent integrals in the gap equation and the pion eigenvalue equation. One is an extended version of the scheme proposed by Lepage and Brodsky and is nearly equivalent to the regularization in the conventional formulation. The other is the one proposed by Lenz, Ohta, Thies and Yazaki and regularizes only the transverse directions while renormalizing the longitudinal direction in the way used for the Gross-Neveu model in the two dimentional world. The latter has been found to give much better results for the pion structure function. It is expected that this formalism will be a step towards a more general framework of describing the chiral symmetry on the light-cone. The nucleon structure function in the relativistic Faddeev approach has been also calculated with the light-cone variables though we have not yet developed the light-cone hamiltonian formalism in this case.In addition to the above, a relativistic harmonic oscillator quark model has been used to study the internal dynamics of a nucleon propagating in the nuclear medium in connection with the problem of color transparency. We have also investigated the interaction between H-dibaryons to examine the possibility of a multi-strangeness baryonic matter. Less