Related papers: On QCD analysis of stucture function $F_2^{\gamma}…
We analyze the perturbative and parametric stability of the QCD predictions for the Callan-Gross ratio $R(x,Q^2)=F_L/F_T$ in heavy-quark leptoproduction. We consider the radiative corrections to the dominant photon-gluon fusion mechanism.…
Photon structure functions in supersymmetric QCD are investigated in terms of the parton model where squark contributions are evaluated. We calculate the eight virtual photon structure functions by taking the discontinuity of the squark…
In recent years, there has been a breakthrough in lattice calculations of $x$-dependent partonic distributions. This encompasses also distributions describing the 3D structure of the nucleon, such as generalized parton distributions (GPDs).…
We present a consistent calculation of the structure functions within a light-front constituent quark model of the nucleon. Relativistic effects and the relevance of the covariance constraints are analyzed for both polarized and unpolarized…
The alternative to the standard formulation of QPM in the infinite momentum frame is suggested. The proposed approach does not require any extra assumptions in addition, consistently takes into account the parton transversal momenta and…
The evolution of polarized quark distribution functions is taken into account the gluon emission and absorption, quark pair production and annihilation processes and treated by a statistical method which provides quark distribution…
We present a determination of the parton distributions of the nucleon from a global set of hard scattering data using the NNPDF methodology at LO and NNLO in perturbative QCD, thereby generalizing to these orders the NNPDF2.1 NLO parton…
The electron and photon structure functions are compared. Advantages of the electron structure function are demonstrated. At very high momenta probabilistic (partonic) interpretation can be preserved despite strong $\gamma$-$Z$…
By introducing ansatz and using a PDF at the $N^3LO$ approximation in this paper, we have studied the structure of the nucleons in generalized parton distributions (GPDs). For this purpose, the form factors and the electric radius of…
The next-to-leading order (NLO) ($\mathcal{O}(\alpha_s^3)$) corrections for gluon fragmentation functions to a heavy quark-antiquark pair in ${^{3}\hspace{-0.6mm}P_{J}^{[1,8]}}$ states are calculated within the NRQCD factorization. We use…
We present a theoretical framework within which both the real and imaginary parts of the complex, two-photon exchange amplitude contributing to $K_L\rightarrow\mu^+\mu^-$ decay can be calculated using lattice QCD. The real part of this…
The current status of global QCD analysis of parton distribution functions of the nucleon is reviewed. Recent progress made in determining various features of the parton structure of the nucleon, as well as outstanding open questions are…
Measurements of the proton and deuteron $F_2$ structure functions are presented. The data, taken at Jefferson Lab Hall C, span the four-momentum transfer range $0.06 < Q^2 < 2.8$ GeV$^2$, and Bjorken $x$ values from 0.009 to 0.45, thus…
A new ''$\mathtt{SK24}$'' non-singlet QCD analysis of the structure functions at the NNLO approximation is performed, utilizing the global fit of the data from various charged lepton scattering experiments. We extract the valence parton…
A new and simple statistical approach is performed to calculate the parton distribution functions (PDFs) of the nucleon in terms of light-front kinematic variables. We do not put in any extra arbitrary parameter or corrected term by hand,…
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…
Nuclear deep inelastic structure functions F_2^A(x,Q^2) as well as parton distribution functions in a nuclei are investigated in the framework of rescaling model. Our analysis is based on analytical expressions for quark and gluon densities…
We investigate different methods to incorporate the effect of photons in hard processes. We compare two different approaches used for calculating cross sections for two-photon $p p \to l^+ l^- X$ process. In one of the approaches photon is…
We calculate the fragmentation function for a light quark to decay into a lepton pair to leading order in the QCD coupling constant. In the formal definition of the fragmentation function, a QED phase must be included in the eikonal factor…
Higher-order QED radiative corrections to muon decay spectrum are evaluated within the QED structure function approach in the next-to-leading order logarithmic approximation. New analytical results are given in the…