AI 中文总结
对质子自旋分解作教学式综述，并讨论了Jaffe-Manohar和Ji分解，强调夸克和胶子轨道角动量，包括规范不变定义、小x行为及与实验可观测量的联系。
AI 中文摘要
本文对质子自旋分解进行了教学式综述。讨论了Jaffe-Manohar分解和Ji分解。特别强调了夸克和胶子的轨道角动量，包括它们的规范不变定义、小x行为以及与实验可观测量的联系。
英文摘要
I present a pedagogical review of the decomposition of the proton spin. Both the Jaffe-Manohar and Ji decompositions are discussed. Particular emphasis is placed on the quark and gluon orbital angular momenta, including their gauge invariant definitions, small-$x$ behavior and connection to experimental observables.
Comments11 pages, contribution to the Encyclopedia of Nuclear Physics
