The Spin Structure of the Proton

Abstract

This article reviews our present understanding of the QCD spin structure of the proton. We first outline the proton spin puzzle and its possible resolution in QCD. We then review the present and next generation of experiments to resolve the proton's spin-flavour structure, explaining the theoretical issues involved, the present status of experimental investigation, and the open questions and challenges for future investigation.

47 pages. To appear in Reviews of Modern Physics

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Cited by in corpus (84)

• An updated review of the new hadron states
• The Spin Structure of the Nucleon
• Large-Momentum Effective Theory
• 50 Years of Quantum Chromodynamics
• Spin and orbital angular momentum in gauge theories (II): QCD and nucleon spin structure
• Hadron structure from lattice quantum chromodynamics
• The Spin Structure of the Nucleon
• Interplay of Spin and Orbital Angular Momentum in the Proton
• Eta bound states in nuclei: a probe of flavour-singlet dynamics
• Is gauge-invariant complete decomposition of the nucleon spin possible ?
• Unquenched quark model for baryons: magnetic moments, spins and orbital angular momenta
• Etaprime and Eta Mesons with Connection to Anomalous Glue
• What can break the Wandzura--Wilczek relation?
• Leading and Next-to-Leading Order Gluon Polarisation in the Nucleon and Longitudinal Double Spin Asymmetries from Open Charm Muoproduction
• The nucleon's octet axial-charge g_A^8 with chiral corrections
• Leading order determination of the gluon polarisation from DIS events with high-p_T hadron pairs
• Disconnected contributions to the spin of the nucleon
• Measurement of the neutron $\beta$-asymmetry parameter $A_0$ with ultracold neutrons
• Understanding the proton's spin structure
• Gluon Gravitational Form Factors at Large Momentum Transfer
• Hyperon Semileptonic decay constants with flavor SU(3) symmetry breaking
• Gluon Polarisation in the Nucleon and Longitudinal Double Spin Asymmetries from Open Charm Muoproduction
• Resummation for Polarized Semi-Inclusive Deep-Inelastic Scattering at Small Transverse Momentum
• The role of the chiral anomaly in polarized deeply inelastic scattering I: Finding the triangle graph inside the box diagram in Bjorken and Regge asymptotics
• Global polarization effect and spin-orbit coupling in strong interaction
• QCD analysis of polarized DIS and the SIDIS asymmetry world data and light sea-quark decomposition
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• Gravitational form factors of the baryon octet with flavor SU(3) symmetry breaking
• Pseudoscalar Meson Decay Constants and Couplings, the Witten-Veneziano Formula beyond large N_c, and the Topological Susceptibility
• The Spin of the Proton
• Quark scalar, axial, and pseudoscalar charges in the Schwinger-Dyson formalism
• Constraints on $s-\bar{s}$ asymmetry of the proton in chiral effective theory
• Baryon Fields with U_L(3) times U_R(3) Chiral Symmetry III: Interactions with Chiral (3,3_bar)+(3_bar,3) Spinless Mesons
• Relativistic spin sum rules and the role of the pivot
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• Spin and orbital angular momentum of the proton
• The First Moments of Nucleon Generalized Parton Distributions
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• Impact of recent COMPASS data on polarized parton distributions and structure functions
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• Proton spin after 30 years: what we know and what we don't?
• Cross sections and double-helicity asymmetries of midrapidity inclusive charged hadrons in p+p collisions at sqrt(s)=62.4 GeV
• Emergent Gauge Symmetries and Particle Physics
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• Spin constraints on Regge predictions and perturbative evolution in high energy collisions
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• Gluon polarization in the proton
• The Jefferson Lab 12 GeV Upgrade
• Upper limit of the total cross section for the pn --> pn eta' reaction
• Non-Singlet spin structure function in the valon model and low x scaling behavior of $g_1^{NS}$ and $g_1^p$
• High-energy physics with particles carrying non-zero orbital angular momentum
• The spin dependent structure functions of the nucleon
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• Running couplings for the simultaneous decoupling of heavy quarks
• Achievements and open issues in the determination of polarized parton distribution functions
• Measurement of the Transverse Single-Spin Asymmetry for Mid-rapidity Production of Neutral Pions in Polarized p+p Collisions at 200 GeV Center-of-Mass Energy
• Gauge invariant gluon spin operator for spinless non-linear wave solutions
• The Gerasimov-Drell-Hearn sum-rule with nuclear targets
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• Quark spin in the proton
• Constituent Quarks and the Spin of the Proton
• Chirality distributions inside baryons in $\mathrm{QC}{\mathrm{D}}_2$
• Truncated first moment of the parton distribution - a modified approach
• Nucleon Spin Structure and Parton Distribution Functions
• Strangeness in the Meson Cloud Model
• Single-inclusive jet production in polarized pp collisions at RHIC to next-to-leading logarithmic accuracy
• Calculation of gluon contribution to the proton spin by using the non-perturbative quantization à la Heisenberg
• Weak Neutral Current Studies with Positrons
• Helicity dependent parton distributions
• Direct $qqq$ Force In High Momentum Limit of QCD For Proton Physics
• On non-parallelism of spin and magnetic moment of proton