Related papers: Integral Relations for Twist 2 abd Twist 3 Contrib…
Different methods to extract the polarized parton densities from the world polarized DIS data are considered. The higher twist corrections $h^N(x)/Q^2$ to the spin dependent proton and neutron $g_1$ structure functions are found to be…
We calculate all twist-two, three and four parton distribution functions involving two quark correlations using the wavefunction of the MIT bag model. The distributions are evolved up to experimental scales and combined to give the various…
We describe a high statistics quenched QCD calculation of the moments of the polarized deep-inelastic structure functions g_1 and g_2 of the proton and neutron.
We report on a recently completed, first calculation of the full next-to-leading order QCD corrections for heavy flavor contributions to the inclusive structure function $g_1$ in longitudinally polarized deep-inelastic scattering. All…
We review the analysis of polarized structure function data using perturbative QCD at next-to-leading order. We use the most recent experimental data to obtain updated results for polarized parton distributions, first moments and the strong…
We compute the contribution from the longitudinally polarized proton to the twist-3 double-spin asymmetry $A_{LT}$ in inclusive (light) hadron production from proton-proton collisions,i.e., $p^\uparrow \vec{p}\to h\,X$. We show that using…
We discuss the spin-dependent structure function $g_2(x,Q^2)$ in the framework of the operator product expansion. It is noted that the anomalous dimensions and coefficient functions for the twist-3 gluon-field-dependent operators depend on…
Deep Inelastic scattering experiments using transversely polarised targets yield information on the structure function $g_2$. By means of a free-field analysis, we study the operator structure of $g_2$ and demonstrate the need for retaining…
We study one-loop contributions to semi-inclusive deep inelastic scattering in the target fragmentation region for a polarized lepton beam and nucleon target. Complete one-loop results at leading twist are derived, with a particular focus…
We present the complete cross-section for the production of unpolarized hadrons in semi-inclusive deep-inelastic scattering up to power-suppressed ${\cal O}(1/Q^2)$ terms in the Wandzura--Wilczek-type approximation which consists in…
We give a general overview of the role and interpretation of fragmentation functions in hard processes. Transverse momentum dependence gives rise to time-reversal odd fragmentation functions contributing at leading order. Final state…
We investigate the consistency between the collinear twist-3 factorization and the transverse-momentum-dependent (TMD) factorization for the transversely polarized hyperon production in semi-inclusive deep inelastic scattering, $ep\to…
The QCD analysis of the $xF_3$ structure function measured in deep-inelastic scattering of neutrinos and antineutrinos on an iron target at the Fermilab Tevatron is done in 1--, 2-- and 3--loop order of QCD. The x dependence of the…
We study the deeply virtual Compton scattering process with both twist-two and twist-three Compton form factors and present our cross-sections formulas with all polarization configurations. While the twist-three contributions are generally…
We review the theory of polarized structure functions measured in deep-inelastic lepton-nucleon scattering, focusing on the most recent developments. We concentrate on the structure function $g_1$, emphasizing the phenomenological problems…
We study the polarized structure functions in QCD. We show that $g_T$ which probes helicity flip interactions in hadrons on the light-front indeed measures the QCD dynamics of chiral symmetry breaking. The relation between chiral symmetry…
Second- and third-order results are presented for the structure functions of charged-current deep-inelastic scattering in the framework of massless perturbative QCD. We write down the two-loop differences between the corresponding…
Modified quark fragmentation functions in deeply inelastic $eA$ collisions and their QCD evolution equations are derived for the first time in the framework of multiple parton scattering. Induced radiation gives rise to additional terms in…
We investigate the renormalization of the twist-3 operators which are relevant for the spin-dependent structure function $g_{2}(x, Q^{2})$. We derive the anomalous dimension for the non-singlet part by calculating the off-shell Green's…
We calculate twist--4 coefficient functions for the deep inelastic structure function $F_2(x,Q^2)$ associated to 4--gluon operator matrix elements for general values of the Bjorken variable $x$ and study the numerical effect on the slope…