Related papers: Truncated Mellin moments: Useful relations and imp…
The review of the nucleon spin structure functions problems is presented. The perturbative QCD predictions for the small x behaviour of the nucleon spin structure functions are discussed. The role of the resummation of the ln^2 1/x terms is…
The spin structure of the system of quasifree fermions having total angular momentum $J=1/2$ is studied in a consistently covariant approach. Within this model the relations between the spin functions are obtained. Their particular cases…
Available analyses on moments of the spin structure function g_1 use different methods and are barely consistent with each other. We present a higher twist analysis of Gamma_1^p using a method consistent with the studies of Gamma_1^n and…
In experiment, the multiplicity distributions of inelastic processes are truncated due to finite energy, insufficient statistics or special choice of events. It is shown that the moments of such truncated multiplicity distributions possess…
Effects of non-linear small-x evolution of the gluon distribution given by the Balitsky-Kovchegov equation are analyzed within the collinear approximation framework. We perform a twist decomposition of the proton structure functions F2 and…
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…
We will discuss recent results for the spin structure functions, with an emphasis on g2 . High precision g2 data allows for tests of the Burkhardt-Cottingham sum rule, and is needed to consistently evaluate higher twist effects.
The structure function $g_1(x,Q^2)$ is analysed within the formalism based on unintegrated spin dependent parton distributions incorporating the LO Altarelli-Parisi evolution and the double $ln^2(1/x)$ resummation at low $x$. We…
It is shown in the framework of the operator product expansion and the renormalization group method that the twist-3 part of flavour nonsinglet spin structure function g_2(x,Q^2) obeys a simple Dokshitzer-Gribov- Lipatov-Altarelli-Parisi…
We show the new relationship [1] between the anomalous dimensions, resummed through next-to-next-to-leading-logarithmic order, in the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations for the first Mellin moments…
Using recent and updated world data on polarized structure functions $g_1$ and $g_2$ we perform QCD analysis at the next-next-to-leading-order (NNLO) accuracy. We include also target mass correction and higher twist effect to get more…
We present a lattice QCD determination of the Mellin moments of the unpolarized gluon parton distribution function in the proton. The analysis is based on matrix elements of nonlocal gluon operators coupled to momentum-boosted proton…
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 Kwiecinski evolution of unintegrated parton distributions (UPDs) in the transverse-coordinate space is analyzed with the help of the Mellin transform. Numerical results are presented for the unintegrated pion distributions with a simple…
Our previous calculation of the spin-dependent structure function g_2 is revisited. The interest in this structure function is to a great extent motivated by the fact that it receives contributions from twist-two as well as from twist-three…
We derive a unitarity relationship between the spin structure function $g_{LT}(x,Q^{2})=g_{1}(x,Q^{2})+g_{2}(x,Q^{2})$, the LT interference diffractive structure function and the spin-flip coupling of the pomeron to nucleons. Our…
We present a calculation of valence double parton distributions of the pion in the framework of chiral quark models. The result obtained at the low-energy quark model scale is particularly simple, where in the chiral limit a factorized form…
Splitting functions govern the scale evolution of parton distribution functions. Through a Mellin transformation, they are related to anomalous dimensions of twist-two operators in the operator product expansion. We study off-shell operator…
We report the results of including resummed splitting functions in the QCD evolution equations at small x, and discuss the predictions that follow for the deep inelastic structure functions. *Contribution at XXX Rencontres de Moriond, Les…
The resummation of $O(\alpha_s^{l+1} \ln^{2l} x)$ terms in the evolution equation of the singlet part of $g_1(x,Q^2)$ is carried out. The corresponding singlet evolution kernels are calculated explicitely. The leading small-$x$ contribution…