2020/09/02 by Xiangdong Ji, Feng Yuan, Ji, Xiangdong +3 · 9 citations
Physics and Astronomy · #Collider #FOS: Physical sciences #Focus (optics) #Gluon #Helicity #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Lattice (hep-lat) #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Muon #Nuclear Experiment (nucl-ex) #Nuclear Theory (nucl-th) #Nuclear physics #Particle physics #Particle physics theoretical and experimental studies #Physics #Proton #Proton spin crisis #Quantum Chromodynamics and Particle Interactions #Quark #Spin (aerodynamics) #hep-ex #hep-lat #hep-ph #nucl-ex #nucl-th
paper · pdf · doi:10.48550/arxiv.2009.01291
published in arXiv (Cornell University) (Cornell University) · 17 pages, 4 figures, to appear in Nature Review
arxiv created 2020/09/02 · openalex publication_date 2020/09/02 · arxiv updated 2020/09/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
More than three decades has passed since the European Muon Collaboration published the first surprising result on the spin structure of the proton. Much theoretical and experimental progress has been made in understanding the origins of the proton spin. In this review, we will discuss what we have learned so far, what are still missing, and what we shall expect to learn from the upcoming experiments including JLab 12 GeV and Electron-Ion Collider. In particular, we focus on first principles calculations and experimental measurements of the total gluon helicity ΔG, and quark and gluon orbital angular momenta.