Related papers: Truncated Mellin moments: Useful relations and imp…
We present a QCD analysis of the twist-three parton distribution functions associated with the spin-orbit correlation of quarks and gluons in spin-$\frac{1}{2}$ and spin-0 hadrons. We derive exact non-perturbative identities decomposing the…
Valence double parton distribution functions of the nucleon are evaluated in the framework of a simple model, where the conservation of the longitudinal momentum is taken into account. The leading-order DGLAP QCD evolution from the low…
Theoretical predictions show that at low values of Bjorken $x$ the spin structure function, $g_1$ is influenced by large logarithmic corrections, $ln^2(1/x)$, which may be predominant in this region. These corrections are also partially…
We present a novel new approach to study quark-hadron duality using truncated moments of structure functions, and determine the degree to which individual resonance regions are dominated by leading twist.
We reanalyze the experimental NMC data on the nonsinglet structure function $F_2^p-F_2^n$ and E866 data on the nucleon sea asymmetry $\bar{d}/\bar{u}$ using the truncated moments approach elaborated in our previous papers. With help of the…
Often the factorization of differential cross sections results in the definition of fundamental hadronic functions/distributions which have a double-scale evolution, as provided by a pair of coupled equations. Typically, the two scales are…
The spin-dependent structure functions g_2 (x, Q^2) are investigated within the framework of the chiral quark soliton model. It turns out that the twist-3 part of g_2 (x, Q^2) gives nonnegligible contributions to the total distributions at…
Polarized structure functions at low $Q^2$ have the physical interpretation of (generalized) spin polarizabilities. At high $Q^2$, the polarized parton distribution $g_2(x)$ provides access to quark-gluon correlations in the nucleon. We…
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…
We perform an extensive study of the scale dependence of flavor-singlet contributions to the structure function g_2(x,Q^2) in polarized deep-inelastic scattering. We find that the mixing between quark-antiquark-gluon and three-gluon twist-3…
New Lorentz Invariance Relations (LIRs) were presented between twist-three Generalized Parton Distributions (GPDs) and transverse momentum, $k_T$, moments of twist-two Generalized Transverse Momentum-Dependent Distributions (GTMDs). By…
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 review the main results on the generalization of the DGLAP evolution equations within the cut Mellin moments (CMM) approach, which allows one to overcome the problem of kinematic constraints in Bjorken $x$. CMM obtained by multiple…
These proceedings contain the 'physical' derivation of the Wandzura-Wilczek relations for the spin-dependent structure function g2 (amounting to keeping the intrinsic transverse momentum of quarks, and neglecting the physical transverse…
The second Mellin moments $\langle x\rangle$ of the nucleon's unpolarized, polarized, and transversity parton distribution functions (PDFs) are computed. Two lattice QCD ensembles at the physical pion mass are used: these were generated…
We demonstrate advantages of the truncated Mellin moments (TMM) approach in the analysis of DIS data. We present a novel method for determination of the Bjorken sum rule (BSR) from restricted in $x$ variable experimental data. We show how…
The spin dependent structure function, g2ww(x,Q^2), is calculated in the valon model. A simple approach is given for the determination of the twist-3 part of the g2(x, Q^2) in Mellin space; thus, enabling us to obtain the full transverse…
The nonsinglet spin dependent structure function $g_2(x,Q^2)$ is studied at small x within the double logarithmic approximation of perturbative QCD. Both positive and negative signature contributions are considered, and we find a power-like…
This paper contains three parts relating to the nucleon spin structure in a simple picture of the nucleon: (i) The polarized gluon distribution in the proton is dynamically predicted starting from a low scale by using a nonlinear QCD…
This thesis is devoted to the study of some aspects of perturbative QCD, and in particular to the development of high-precision techniques for the extraction of physical parameters such as structure functions, parton distributions, and the…