Nucleon spin structure and pQCD frontier on the move

Abstract

The interplay between higher orders of the perturbative QCD (pQCD) expansion and higher-twist contributions in the analysis of recent Jefferson Lab data on the lowest moment of the spin-dependent proton ${\Gamma }_1^p(Q^2)$ at $0.05<Q^2<3{\mathrm{GeV}}^2$ is studied. We demonstrate that the values of the higher-twist coefficients ${\mu }_{2k}^{p,n}$ extracted from the data by using the singularity-free analytic perturbation theory provide a better convergence of the higher-twist series than with the standard perturbative QCD. From the high-precision proton data, we extract the value of the singlet axial charge $a_0(1{\mathrm{GeV}}^2)=0.33\pm 0.05$. We observe a slow $Q^2$ dependence of fitted values of the twist coefficient ${\mu }_4$ and $a_0$ when going to lower energy scales, which can be explained by the renormalization group evolution of ${\mu }_4(Q^2)$ and $a_0(Q^2)$. As the main result, a good quantitative description of all the Jefferson Lab data sets down to $Q \simeq 350 MeV is achieved.

21 pages, 12 figures, references added, minor corrections

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• The Deuteron Spin-dependent Structure Function g1d and its First Moment
• Global Analysis of Helicity Parton Densities and Their Uncertainties
• Spin Structure of the Nucleon - Status and Recent Results
• On the running coupling constant in QCD
• Ten years of the Analytic Perturbation Theory in QCD
• Determination of the effective strong coupling constant alpha_{s,g_1}(Q^2) from CLAS spin structure function data
• Determination of gluon polarization from deep inelastic scattering and collider data
• Impact of CLAS and COMPASS data on Polarized Parton Densities and Higher Twist
• Bound state approach to the QCD coupling at low energy scales
• Small-x behavior of the structure function F_2 and its slope partial ln(F_2)/partial ln(1/x) for "frozen" and analytic strong-coupling constants
• Experimental study of isovector spin sum rules
• Bjorken Sum Rule and pQCD frontier on the move
• Phenomenological analysis of the nucleon spin contents and their scale dependence
• Analytic Perturbation Theory Model for QCD and Upsilon Decay

Cited by in corpus (42)

• Determination of Polarized PDFs from a QCD Analysis of Inclusive and Semi-inclusive Deep Inelastic Scattering Data
• The Spin-dependent Structure Function of the Proton g_1^p and a Test of the Bjorken Sum Rule
• The Spin Structure of the Nucleon
• High precision determination of the $Q^2$-evolution of the Bjorken Sum
• Four-loop QCD analysis of the Bjorken sum rule vs data
• Analogs of noninteger powers in general analytic QCD
• Determination of the Proton Spin Structure Functions for 0.05 < Q^2 < 5 GeV^2 using CLAS
• FAPT: a Mathematica package for calculations in QCD Fractional Analytic Perturbation Theory
• Bjorken polarized sum rule and infrared-safe QCD couplings
• Nearly perturbative lattice-motivated QCD coupling with zero IR limit
• Nucleon spin structure at low momentum transfers
• Reconciling the analytic QCD with the ITEP operator product expansion philosophy
• Simple analytic QCD model with perturbative QCD behavior at high momenta
• QCD coupling constant at NNLO from DIS data
• Operator Product Expansion with analytic QCD in tau decay physics
• Calculation of binding energies and masses of quarkonia in analytic QCD models
• Renormalon-motivated evaluation of QCD observables
• Polarized electron-deuteron deep-inelastic scattering with spectator nucleon tagging
• Bjorken sum rule in QCD frameworks with analytic (holomorphic) coupling
• Measurement of the 3He Spin-Structure Functions and of Neutron (3He) Spin-Dependent Sum Rules at 0.035<Q^2<0.24 GeV^2
• How to perform QCD analysis of DIS in Analytic Perturbation Theory
• Lattice-motivated holomorphic nearly perturbative QCD
• QCD rescattering mechanism for diffractive deep inelastic scattering
• Fractional Analytic QCD beyond Leading Order
• Improved nonsinglet QCD analysis of the fixed-target DIS data
• Fractional Analytic QCD beyond Leading Order in timelike region
• Optimized determination of the polarized Bjorken sum rule in pQCD
• Bjorken sum rule in QCD with analytic coupling
• Lattice-motivated QCD coupling and hadronic contribution to muon $g-2$
• A novel determination of non-perturbative contributions to Bjorken sum rule
• Perturbative QCD in acceptable schemes with holomorphic coupling
• Cut Moments approach in the analysis of DIS data
• Infrared-suppressed QCD coupling and the hadronic contribution to muon g-2
• Nonsinglet polarized nucleon structure function in infrared-safe QCD
• Evaluation of neutrinoless double beta decay: QCD running to sub-GeV scales
• On applications of Mathematica Package "FAPT" in QCD
• pQCD running couplings finite and monotonic in the infrared: when do they reflect the holomorphic properties of spacelike observables?
• Inevitability and Importance of Non-Perturbative Elements in Quantum Field Theory
• Resummation Approach in QCD Analytic Perturbation Theory
• Small-x behavior of non-singlet spin structure function and Bjorken sum rule with pQCD correction up to NNLO and Higher twist correction
• Measurement of the nucleon spin structure functions for 0.01<$Q^2$<1 GeV${}^2$ using CLAS
• Experimental studies at low $Q^2$ of the spin structure of the nucleon at Jefferson Lab