Related papers: The Singlet Contribution to the Structure Function…
The singlet contribution to the $g_1(x,Q^2)$ structure function is calculated in the double-logarithmic approximation of perturbative QCD in the region $x \ll 1$. Double logarithmic contributions of the type $(\alpha_s \ln ^2 (1/x))^k$…
The resummation of $O(\alpha_s^{l+1} \ln^{2l} x)$ terms in the evolution kernels of non--singlet combinations of unpolarized and polarized structure functions is investigated. The agreement with complete calculations up to order…
The small-x behavior of the singlet contributions to the polarized structure function g_2(x,Q^2) is calculated in the double-logarithmic approximation of perturbative QCD. The dominant contribution is due to the gluons which, in contrast to…
We report a semi-analytical approach for the solution of the nonlinear Gribov-Levin-Ryskin-Mueller-Qiu (GLR-MQ) evolution equation for sea quark distribution and investigate the effect of gluon shadowing on the small-x and moderate-Q^2…
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…
The large-x behavior of the physical evolution kernels appearing in the second order evolution equations of the singlet F_2 structure function and of the F_{phi} structure function in phi-exchange DIS is investigated. The validity of a…
We calculate the one-loop twist-3 gluon contribution to the flavor-singlet structure function g_2(x,Q^2) in polarized deep-inelastic scattering and find that it is dominated by the contribution of the three-gluon operator with the lowest…
Explicit expressions for the singlet g_1 at small x and small Q^2 are obtained with the total resummation of the leading logarithmic contributions. It is shown that g_1 practically does not depend on Q^2 in this kinematic region. In…
We have estimated the contributions to the moments of polarized nucleon structure function $g_1(x,Q^2)$ coming from the region of the very low x ($10^{-5}<x$). Our approach uses the nucleon structure function extrapolated to the region of…
Nonsinglet contributions to the $g_1(x,Q^2)$ structure function are calculated in the double-logarithmic approximation of perturbative QCD in the region $x \ll 1$. Double logarithmic contributions of the type $(\alpha_s \ln ^2 (1/x))^k$…
The numerical effects of the known all-order leading and next-to-leading logarithmic small-$x$ contributions to the anomalous dimensions and coefficient functions of the unpolarized singlet evolution are discussed for the structure…
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…
The resummation of $O(\alpha^{l+1} \ln^{2l} x)$ terms in the evolution kernels of non--singlet combinations of structure functions is investigated for both QED abd QCD. Numerical results are presented for unpolarized and polarized structure…
The running of the QCD coupling is incorporated into the infrared evolution equations for the flavour structure function g_1. The explicit expressions for g_1 including the total resummation of the double-logarithmic contributions and…
We review small $x$ contributions to perturbative evolution equations for parton distributions, and their resummation. We emphasize in particular the resummation technique recently developed in order to deal with the apparent instability of…
A brief survey is given of recent results on the resummation of leading small-x terms for unpolarized and polarized non--singlet and singlet structure function evolution.
Explicit expressions for the non-singlet and singlet structure functions g_1 in the small-x region are obtained. They include the total resummation of the double- and single- logarithms of x and account for the running QCD coupling effects.…
The explicit expressions for the non-singlet DIS structure functions obtained at small x by resumming the most singular logarithmic contributions are discussed and compared in detail with the DGLAP evolution for different values of x and…
Explicit expressions for the non-singlet and singlet structure functions g_1 at the small $x$-region are obtained. They include the total resummation of double-logarithmic contributions and accounting for the running QCD coupling effects.…
A systematic study is performed of the impact of the various resummed small-$x$ contributions to the anomalous dimensions and coefficient functions on the evolution of unpolarized structure functions in deep-inelastic scattering. The proton…