A model for the $Q^2$ dependence of polarized structure functions

Abstract

We present an update of a phenomenological model for the spin dependent structure functions $g_1(x,Q^2)$ of the proton and neutron. This model is based on a broken SU(6) wavefunction parametrized by the unpolarized structure functions. The two free parameters of the model are choosen to fulfill the Bjorken and Ellis--Jaffe sum rules. The model respects isospin symmetry and has zero strange sea polarization. Using new values for $F/D$ from hyperon beta decay the resulting $Q^2$ dependent asymmetries $A_1$ are in perfect agreement with the existing data. Therefore we do not see any evidence for a ``spin crisis''. With two choices for $g_2$ the $Q^2$ dependence of $A_1(x,Q^2)$ and $A_2(x,Q^2)\sqrt{Q^2}/M$ is predicted and shown to be small for both cases.

18 pages and 11 figures as uudecoded ps files

References in corpus (13)

• The three-loop QCD $\beta$-function and anomalous dimensions
• Measurement of the Spin-Dependent Structure Function $g_1(x)$ of the Proton
• QCD Constrains on the Shape of Polarized Quark and Gluon Distributions
• ERRATUM TO: Power corrections $1/Q^2$ to parton sum rules for deep inelastic scattering from polarized targets
• The next-to-leading QCD approximation to the Ellis-Jaffe sum rule
• QCD Sum Rule Calculation of Twist-3 Contributions to Polarized Nucleon Structure Functions
• Spin-dependent Parton Distributions from Polarized Structure Function Data
• On the Q^2 Dependence of Measured Polarized Structure Funtions
• Scale Dependence and Small-x Behaviour of Polarized Parton Distributions
• OPE analysis for polarized deep inelastic scattering
• Reanalysis of hyperon beta decay data on $F/D$
• Polarised parton distributions
• Sea-quark Content of Nucleons from Proton-induced Drell-Yan Production

Cited by in corpus (8)

• Measurements of the Proton and Deuteron Spin Structure Functions g1 and g2
• Precision Measurement of the Proton and Deuteron Spin Structure Functions g2 and Asymmetries A2
• Measurements of the Proton and Deuteron Spin Structure Function g2 and Asymmetry A2
• Measurement of the Proton and Deuteron Spin Structure Functions g2 and Asymmetry A2
• Reanalysis of hyperon beta decay data on $F/D$
• An Analysis of the Next-to-Leading Order Corrections to the g_T(=g_1+g_2) Scaling Function
• Resonances and higher twist in polarized lepton-nucleon scattering
• Target mass corrections and twist-3 in the nucleon spin structure functions