Related papers: Polarized Structure Functions: a Theoretical Updat…
A recent lattice calculation of the spin-dependent structure function g_2 is revisited. It has been recognized that the twist-three operator, which gives rise to d_2, mixes non-perturbatively with operators of lower dimensions under…
The status of the twist--2 and the twist--3 integral relations between polarized structure functions in deep inelastic scattering for electromagnetic and electroweak interactions is reviewed. One novel integral relation for the twist--3…
Using the framework of QCD sum rules we predict the twist-3 contribution to the second moment of the polarized nucleon structure function $g_2(x)$. As the relevant local operator depends explicitely on the gluon field, we employ a recently…
Reports on our latest extractions of parton distribution functions of the nucleon are given. First an overview of the recent JR14 upgrade of our unpolarized PDFs, including NNLO determinations of the strong coupling constant and a…
We discuss the determination of polarized parton distributions from a next-to-leading order analysis of recent experimental data. We extract the first moment of the polarized quark and gluon distribution and assess the corresponding…
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…
Spin-1 hadrons contain different aspects of spin physics from the ones of the spin-1/2 nucleon because of the existence of tensor-polarized structure functions. In the charged-lepton deep inelastic scattering from a spin-1 hadron or…
In the context of noncommutative space-time, we investigate the nucleon structure functions which plays an important role to identify the internal structure of nucleons. We use the corrected vertices and employ new vertices that appear in…
Determinations of structure functions and parton distribution functions have been recently obtained using Monte Carlo methods and neural networks as universal, unbiased interpolants for the unknown functional dependence. In this work the…
The polarized photon structure is described by two spin structure functions $g_1^\gamma$ and $g_2^\gamma$ which can be studied in the future polarized ep or e$^+$e$^-$ colliders. Here we investigate the QCD twist-3 effects in $g_2^\gamma$…
We briefly discuss recent results on the evolution of unpolarized parton densities and structure functions in massless perturbative QCD. Present partial results on the next-to-next-to-leading order (NNLO) evolution kernels prove sufficient…
In the Framework of {\it{valon model}} we have calculated the parton distribution in a valon for both the polarized and unpolarized cases. These distributions are originated purely from the dressing of a valence quark in QCD and are common…
We have studied the deep inelastic scattering (DIS) of polarized charged leptons from polarized nucleon targets and evaluated the polarized nucleon structure functions $g_{1N,2N}(x,Q^2)$ as well as the nucleon asymmetries $A_{1N,2N}(x,Q^2)$…
The twist 2 and twist 3 contributions of the polarized deep-inelastic structure functions are calculated both for neutral and charged current interactions using the operator product expansion in lowest order in QCD. The relations between…
The size of higher twist corrections to the spin proton and neutron g1 structure functions and their role in determining the polarized parton densities in the nucleon is discussed.
We derive relations between spin-dependent nuclear and nucleon g_1 and g_2 structure functions within the nuclear impulse approximation, which are valid at all Q^2, and in both the resonance and deep inelastic regions. We apply the…
The Pauli exclusion principle is advocated for constructing the proton and neutron deep inelastic structure functions in terms of Fermi-Dirac distributions that we parametrize with very few parameters. It allows a fair description of the…
The flux of papers from electron positron colliders containing data on the photon structure function ended naturally around 2005. It is thus timely to review the theoretical basis and confront the predictions with a summary of the…
The nonperturbative $Q^2$- dependence of the sum rules for the structure functions of polarized $e(\mu)N$ scattering is discussed. The determination of twist-4 corrections to the structure functions at high $Q^2$ by QCD sum rules is…
An overview of the SMC data taking and the polarized deep inelastic scattering experiment is given. The new data on the deuteron extend the kinematic range and have considerably reduced statistical and systematic errors. The evaluation of…