Related papers: QCD effective charge and the structure function $F…
HERA $ep$ collider provides unique information on the proton structure. High center of mass energy $s=320$ GeV gives access to both the low Bjorken-$x$ domain and regime of high momentum transfers $Q$. Recently the H1 collaboration reported…
We analyse the data for the proton structure function $F_2$ over the entire $Q^2$ domain, including especially low $Q^2$, in terms of perturbative and non-perturbative QCD contributions. The small distance configurations are given by…
The $n$-th moments of the nuclear structure function $F_2^A(x,Q^2)$ are analyzed using the off-shell kinematics appropriate to describe deep inelastic electron-nucleus scattering within the impulse approximation. It is shown that off-shell…
We consider power-behaved contributions to hard processes in QCD arising from non-perturbative effects at low scales which can be described by introducing the notion of an infrared-finite effective coupling. Our method is based on a…
We describe the determination of the heavy quarks structure functions $F_{2,L}^{\mathcal{Q}\bar{\mathcal{Q}}}$ with help of the scaling properties. We observe that the structure functions for inclusive charm and bottom production exhibits…
A surprisingly good holographic description of QCD can be obtained from naive five dimensional gauge theory on a truncated AdS space. We seek to improve the infra-red description of QCD in such models by using a more sophisticated metric…
In the leading twist approximation of the Wilson operator product expansion with standard and "frozen" versions of strong copling constant we show that the Bessel-inspired behavior of the structure function $F_2$ at small $x$, obtained for…
We discuss the distinct approaches for high density QCD (hdQCD) in the asymptotic regime of large values of parton density. We derive the AGL equation for running coupling constant and obtain the asymptotic solution, demonstrating that the…
In this thesis, we have presented some of the aspects of light-front (LF) field theory through their successful application in the Deep Inelastic Scattering (DIS). We have developed a LFQCD Hamiltonian description of the DIS structure…
We propose a generalization of Grunberg's method of effective charges in which, starting with the effective charge for some dimensionless QCD observable dependent on the single energy scale $Q, R(Q)$, we introduce an infinite set of…
A QCD based effective action is constructed to describe the dynamics of confinement and symmetry breaking in the process of parton-hadron conversion. The deconfined quark and gluon degrees of freedom of the perturbative QCD vacuum are…
Measurements of proton structure functions made in neutral and charged current interactions at HERA are discussed, covering four-momentum transfers Q^2 from about 0.5 GeV^2 to 30000 GeV^2. The results include the rise of the structure…
We present estimates of possible data on spin-dependent asymmetries in inclusive scattering of high energy polarized electrons by high energy polarized protons at HERA with their statistical errors and discuss systematic errors. We show…
In the leading twist approximation of the Wilson operator product expansion with "frozen" and analytic strong coupling constants we show that Bessel-inspired behavior of the structure function F2 at small x, obtained for a flat initial…
The H1 and ZEUS Collaborations have performed new next-to-leading order QCD analyses to determine the parton density functions of the proton. QCD fits are performed using inclusive neutral and charged deep inelastic scattering cross…
We use the unintegrated Parton Density Functions of the gluon obtained from a fit to measurements of the structure functions F2 and F2c at HERA to describe the experimental data for F2b, FL and FL at fixed W.
Higher twist effects in the deeply inelastic scattering are studied. We start with a short review of the theoretical results on higher twists in QCD. Within the saturation model we perform a twist analysis of the nucleon structure functions…
We compare recent experimental results for one-particle-inclusive processes in deeply inelastic scattering at HERA with theoretical predictions in next-to-leading-order QCD perturbation theory, and study the factorization scale dependence…
We show that recent data from HERA on the proton structure function $F_2$ at small $x$ and large $Q^2$ provide a direct confirmation of the double asymptotic scaling prediction of perturbative QCD. A linear rise of $\ln F_2$ with the…
We compute the coefficient function for the charge-averaged W^(+/-)-exchange structure function F_3 in deep-inelastic scattering (DIS) to the third order in massless perturbative QCD. Our new three-loop contribution to this quantity forms,…