Related papers: The Running Coupling BFKL Anomalous Dimensions and…
We present an analysis of the role of the running coupling constant at the intersection of perturbative and nonperturbative QCD. Although the approaches that have been considered so far in these two regimes appear to be complementary to…
We discuss the BFKL equation with a running gauge coupling and identify in its solutions the contributions originating from different transverse momentum scales. We show that for a running coupling constant the distribution of the gluons…
We present the scheme-invariant unpolarized and polarized flavor non-singlet evolution equation to N$^3$LO for the structure functions $F_2(x,Q^2)$ and $g_1(x,Q^2)$ including the charm- and bottom quark effects in the asymptotic…
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…
We present the next-to-next-to-leading order (NNLO) contributions to the main splitting functions for the evolution of longitudinally polarized parton densities of hadrons in perturbative QCD. The quark-quark and gluon-quark splitting…
We present a global fit to the structure function F_2 measured in lepton-proton experiments at small values of Bjorken-x, x< 0.01, for all experimentally available values of Q^2, 0.045< Q^2 < 800 GeV^2, using the Balitsky -Kovchegov…
The perturbative QCD predictions concerning deep inelastic scattering at low $x$ are summarized. The theoretical framework based on the leading log $1/x$ resummation and $k_t$ factorization theorem is described and some recent developments…
By using $\k$-factorization, we derive resummation formulas for the non-abelian $q\bar{q}$ contributions to both heavy flavour production by gluon fusion, and to the next-to-leading BFKL kernel. By combining this result with previous ones…
The impact of the resummed next-to-leading logarithmic small-$x$ contributions to the anomalous dimension $\gamma_{gg}$ is evaluated for the unpolarized parton densities and structure functions of the nucleon. These new terms diminish the…
We discuss DGLAP and BFKL evolution equations in the N=4 supersymmetric gauge theory in the leading and next-to-leading approximations. Eigenvalues of the BFKL kernel in this model turn out to be analytic functions of the conformal spin. It…
A feasible mechanism of unitarization of amplitudes of deep inelastic scattering at small values of Bjorken $x$ is the gluon fusion. However, its efficiency depends crucially on the vacuum color screening effect which accompanies the…
High-energy scattering in pQCD in the Regge limit is described by the evolution of Wilson lines governed by the BK equation. In the leading order, the BK equation is conformally invariant and the eigenfunctions of the linearized BFKL…
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…
Using Laplace transform techniques, I calculate the longitudinal structure function $F_{L}(x,Q^{2})$ from the scaling violations of the proton structure function $F_{2}(x,Q^{2})$, and make a critical study of this relationship between the…
We calculate structure functions at small $x$ both under the assumption of a hard singularity (a power behaviour $x^{-\lambda}, \lambda$ positive, for $x\rightarrow 0$) or that of a soft-Pomeron dominated behaviour, also called double…
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 QCD analytic running coupling alpha_{an} which has no nonphysical singularities for all Q^2>0 is considered for the initial perturbation theory approximations up to four loop order. The finiteness of the analytic coupling at zero is…
We study two-to-two parton scattering amplitudes in the high-energy limit of perturbative QCD by iteratively solving the BFKL equation. This allows us to predict the imaginary part of the amplitude to leading-logarithmic order for arbitrary…
We study next-to-leading corrections to the integral kernel of the BFKL equation for high energy cross-sections in QCD and in supersymmetric gauge theories. The eigenvalue of the BFKL kernel is calculated in an analytic form as a function…
We compute the fully-differential B -> X_u l nu decay width to all orders in perturbation theory in the large-beta0 limit. Each of the five structure functions that build the hadronic tensor is expressed as a Borel integral, summing up O(CF…