标题： 重子自旋与产生强子质量 显示英文标题

标题： Baryon Spin and Emergent Hadron Mass

摘要： 本文描述了利用戴森-施温格方程（DSEs）研究QCD中的重子束缚态。在这项工作中，八重态重子的轴向形式因子是通过矢量$\times$矢量接触相互作用（SCI）的对称性保持处理来计算的。这些重子被视为夸克加相互作用二夸克束缚态，其结构（波函数）是通过求解一个庞加莱协变的法德耶夫方程得到的。由于它保持了对称性，部分守恒轴流的所有后果都是显而易见的。例如，发现八重态重子的轴向性质与SU(3)味对称性的微小违反是一致的，这被解释为新兴强子质量（EHM）的动力学结果。考虑中性轴流时，SCI给出了八重态重子轴向电荷的味分离预测，并因此产生了相关的SU(3)单态、三重态和八重态轴向电荷的值。结果表明，在强子尺度$\zeta_{\mathcal{H}}$上，价自由度携带了大约$50\%$的八重态重子总自旋。质子结构是强子物理的主要课题之一。对其研究有望揭示质量和强相互作用动力学起源的关键特征。因此，这项工作将上述分析扩展到对质子内部部分子螺旋度（自旋）分布函数（DFs）的研究。使用质子极化价夸克分布函数的假设，对测量尺度$\zeta_{\rm C}^2 = 3\,$GeV$^2$下的所有质子极化分布函数进行了预测。预测分布函数的逐点行为及其矩与从数据推断的结果有很好的一致性。基于这些结果，可以得出实验测量质子味单态轴向电荷应返回值$a_0^{\rm E}(\zeta_{\rm C}) = 0.35(2)$。 显示英文摘要

摘要： This thesis describes the use of Dyson-Schwinger equations (DSEs) to study baryon bound states in QCD. In this work, octet baryon axial form factors are calculated using a symmetry-preserving treatment of a vector $\times$ vector contact interaction (SCI). The baryons are considered as quark-plus-interacting-diquark bound states, whose structure (wave function) is obtained by solving a Poincar\'e-covariant Faddeev equation. Since it preserves symmetries, all consequences of partial conservation of the axial current are manifest. For instance, one finds that octet baryon axial properties are consistent with only minor violations of SU(3)-flavour symmetry, being interpreted as a dynamical consequence of emergent hadron mass (EHM). Considering neutral axial currents, the SCI delivers predictions for the flavour separation of octet baryon axial charges and, consequently, produces values for the associated SU(3) singlet, triplet, and octet axial charges. The results indicate that, at the hadron scale $\zeta_{\mathcal{H}}$, valence degrees of freedom carry approximately $50\%$ of an octet baryon's total spin. Proton structure is one of the principal topics in hadron physics. Its study is expected to reveal key features of both the origin of mass and strong interaction dynamics. This work therefore extended the above analyses to an examination of in-proton parton helicity (spin) distribution functions (DFs). Using Ans\"atze for hadron-scale proton polarised valence quark DFs, predictions are delivered for all proton polarised DFs at the measurement scale $\zeta_{\rm C}^2 = 3\,$GeV$^2$. The pointwise behaviour of the predicted DFs and, consequently, their moments, shows good agreement with results inferred from data. Based on these results, one finds that experimental measurements of the proton flavour-singlet axial charge should return a value $a_0^{\rm E}(\zeta_{\rm C}) = 0.35(2)$.