Study of chiral symmetry and internal structure of the nucleon

核子手性对称性和内部结构的研究

• 批准号: 08640355
• 负责人: YAZAKI Koichi
• 金额: $ 1.34万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08640355/
• 关键词: chiral symmetry; NJL model; light-cone coordinate; structure function; color transparency; H-dibaryon; Hダイバリオン; 核物質状態方程式; 1; Nc展開; 正則化; Faddeev方程式; 軸性ベクトル結合定数; 陽子のスピン期待値; 磁気モーメント; 電荷半径; 平均場近似; 真空偏極

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

本研究的目的是在NJL模型的基础上扩展我们以前对核子内部结构的研究，通过计算结构函数来考察该模型的动力学方面，并研究核介质中核子内部结构的变化。由于光锥形式是计算结构函数最方便的形式，我们发展了NJL模型的光锥哈密顿形式。光锥上费米子的一个特征是它们的动力学分量的数量变成通常公式的一半，并且在存在相互作用的情况下消除非动力学分量并不是微不足道的。我们引入了对应于标量介子和伪标量介子的辅助场来处理这个问题。然后用1/N展开求解辅助场的约束方程，给出最低阶的间隙方程和次阶的哈密顿量中的相互作用项。皮奥…该方案中更多的n由夸克-反夸克系统的Tamm-Dancoff方程描述，本征函数与介子结构函数直接相关。我们考虑了两种正则化方案来处理间隙方程和介子本征值方程中的发散积分。其中一种方案是由LPage和Brodsky提出的方案的扩展版本，它与传统公式中的正则化方法几乎等价。另一种是Lenz，Ohta，Thies和Yazaki提出的方法，它只正规化横向，而重整化纵向，就像格罗斯-内沃模型在二维世界中所用的那样。后者已被发现对介子结构函数给出了更好的结果。预计这种形式主义将是朝着描述光锥上手征对称性的更一般框架迈出的一步。相对论Faddeev方法中的核子结构函数也是用光锥变量计算的，尽管我们还没有在这种情况下发展光锥哈密顿形式。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输的内部动力学。我们还研究了H-双重子之间的相互作用，以考察多重奇异性重子物质的可能性。较少

项目成果

Ishii,N.,Asami,H.,Bentz,W.,Yazaki,K.: "Faddeev approach to the nucleon in the NJL model" Austral.Journ.Phys.50. 123-130 (1997)

Ishii,N.、Asami,H.、Bentz,W.、Yazaki,K.：“NJL 模型中核子的 Faddeev 方法”Austral.Journ.Phys.50。

Bentz,W.,Moneo,H.,Asami,H.,Ishii,N.,Yazaki,K.: "Relativistic Faddeev description of baryons and nueleon structure function in the NJL model" Proc.of 1998 YITP Workshop on QCD and Hadron Physics,World Scientific. (to be published).

Bentz,W.,Moneo,H.,Asami,H.,Ishii,N.,Yazaki,K.：“NJL 模型中重子和核子结构函数的相对论 Faddeev 描述”Proc.of 1998 YITP 研讨会 QCD 和强子

T.Sakai, J.Mori, A.Buchmann, K.Shimizu and K.Yazaki: "The interaction between H-dibaryons" Nucl.Phys.A 625. 192-206 (1997)

T.Sakai、J.Mori、A.Buchmann、K.Shimizu 和 K.Yazaki：“H-二重子之间的相互作用”Nucl.Phys.A 625. 192-206 (1997)

ベンツ,ヴォルフガング: "Relativistic Faddeev Approach to Baryons in the Nambu-Jona-Lasinio(NJL)model" Prog.Part.Nucl.phys.36. 179-188 (1996)

Benz，Wolfgang：“Nambu-Jona-Lasinio（NJL）模型中重子的相对论法德耶夫方法”Prog.Part.Nucl.phys.36（1996）。

W.Bentz: "Baryons in the NJL Model as Solutions of the Relativistic Faddeev Equation" Journal of the Korean Physical Society (Proc.Suppl.). 29. S352-S354 (1996)

W.Bentz：“NJL 模型中的重子作为相对论 Faddeev 方程的解”，韩国物理学会期刊（Proc.Suppl.）。