Global Analysis of Data on the Proton Structure Function g1 and Extraction of its Moments

Abstract

Inspired by recent measurements with the CLAS detector at Jefferson Lab, we perform a self-consistent analysis of world data on the proton structure function g1 in the range 0.17 < Q2 < 30 (GeV/c)**2. We compute for the first time low-order moments of g1 and study their evolution from small to large values of Q2. The analysis includes the latest data on both the unpolarized inclusive cross sections and the ratio R = sigmaL / sigmaT from Jefferson Lab, as well as a new model for the transverse asymmetry A2 in the resonance region. The contributions of both leading and higher twists are extracted, taking into account effects from radiative corrections beyond the next-to-leading order by means of soft-gluon resummation techniques. The leading twist is determined with remarkably good accuracy and is compared with the predictions obtained using various polarized parton distribution sets available in the literature. The contribution of higher twists to the g1 moments is found to be significantly larger than in the case of the unpolarized structure function F2.

18 pages, 13 figures, to appear in Phys. Rev. D

References in corpus (19)

• Big Bang Nucleosynthesis (in "The Review of Particle Properties" 2004)
• The ratio of proton's electric to magnetic form factors measured by polarization transfer
• Models for the Polarized Parton Distributions of the Nucleon
• Measurements of the $Q^2$-Dependence of the Proton and Neutron Spin Structure Functions g1p and g1n
• QCD Analysis of Polarized Deep Inelastic Data and Parton Distributions
• Precision Measurement of the Proton and Deuteron Spin Structure Functions g2 and Asymmetries A2
• Next-to-next-to-leading logarithmic threshold resummation for deep-inelastic scattering and the Drell-Yan process
• gamma* N -> Delta transition form factors: a new analysis of the JLab data on p(e,e'p)pi0 at Q^2=2.8 and 4.0 (GeV/c)^2
• Measurement of the Proton Spin Structure Function $g_1(x,Q^2)$ for $Q^2$ from 0.15 to 1.6 GeV${}^2$ with CLAS
• A New Evaluation of Polarized Parton Densities in the Nucleon
• A Kinematically Complete Measurement of the Proton Structure Function F2 in the Resonance Region and Evaluation of Its Moments
• Leading and higher twists in the proton polarized structure function at large Bjorken x
• Inclusive and Semi-Inclusive Polarized DIS Data Revisited
• Moments of the Proton F2 Structure Function at Low Q2
• On the Role of Higher Twist in Polarized Deep Inelastic Scattering
• Higher twist analysis of the proton g_1 structure function
• Soft gluon effects in the extraction of higher twists at large Bjorken x
• Positivity constraints and flavor dependence of higher twists
• New extraction of alpha_s(MZ) from proton DIS data

Cited by in corpus (19)

• Spin Structure of the Nucleon - Status and Recent Results
• Proton structure corrections to electronic and muonic hydrogen hyperfine splitting
• Moments of the Spin Structure Functions g_1^p and g_1^d for 0.05 < Q^2 < 3.0 GeV^2
• QCD resummation for semi-inclusive hadron production processes
• Investigation of the Second Moment of the Nucleon's g1 and g2 Structure Functions in Two-Flavor Lattice QCD
• R-evolution: Improving perturbative QCD
• Soft-gluon resummation effects on parton distributions
• Target mass corrections revisited
• Probing Quark-Gluon Interactions with Transverse Polarized Scattering
• Measurement of the Deuteron Structure Function F2 in the Resonance Region and Evaluation of Its Moments
• Fit to the Bjorken, Ellis-Jaffe and Gross-Llewellyn-Smith sum rules in a renormalon based approach
• Lattice results for the longitudinal spin structure and color forces on quarks in a nucleon
• Role of Positivity Constraints in Determining Polarized Parton Densities
• Threshold resummation for polarized (semi-)inclusive deep inelastic scattering
• Target mass corrections and twist-3 in the nucleon spin structure functions
• Target mass corrections to matrix elements in nucleon spin structure functions
• Transverse Spin Structure Function g2(x, Q2 ) in the Valon model
• The Jlab Upgrade - Studies of the Nucleon with CLAS12
• Updated Determination of Ellis-Jaffe Sum Rules up to ${\mathrm{N}}^3\mathrm{LO}$ QCD corrections