2009/12/23 by M Burkardt, Matthias Burkardt, C A Miller +2 · 100 citations
Physics and Astronomy · #Electron #High-Energy Particle Collisions Research #Lepton #Nuclear physics #Nucleon #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quantum mechanics #Scattering #Spin (aerodynamics)
paper · doi:10.1088/0034-4885/73/1/016201
published in Reports on Progress in Physics 73(1), 016201 (IOP Publishing)
openalex publication_date 2009/12/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
The proton is a composite object with spin one-half, understood to contain highly relativistic spin one-half quarks exchanging spin-one gluons, each possibly with significant orbital angular momenta.While their fundamental interactions are well described by quantum chromodynamics (QCD), our standard theory of the strong interaction, non-perturbative calculations of the internal structure of the proton based directly on QCD are beginning to provide reliable results.Most of our present knowledge of the structure of the proton is based on experimental measurements interpreted within the rich framework of QCD.An area presently attracting intense interest, both experimental and theoretical, is the relationship between the spin of the proton and the spins and orbital angular momenta of its constituents.While remarkable progress has been made, especially in the last decade, the discovery and investigation of new concepts have revealed that much more remains to be learned.