Related papers: The Charm Quark Contribution to the Proton Structu…
We present an unbiased determination of the charm content of the proton, in which the charm parton distribution function (PDF) is parametrized on the same footing as the light quarks and the gluon in a global PDF analysis. This…
We present our QCD analysis of the proton structure function $F_2^p(x,Q^2)$ to determine the parton distributions at the next-to-leading order (NLO). The heavy quark contributions to $F_2^i(x,Q^2)$, with $i$ = $c$, $b$ have been included in…
Gravitational form factors (GFFs) of hadrons encode essential information about the internal distributions of mass, spin, pressure, and shear among their quark and gluon constituents. We compute the quark and gluon GFFs of the proton using…
In recent years, Fractal Inspired Models of quark and gluon densities at small x have been proposed. In this paper, we investigate longitudinal structure function F-L (x, Q2) within this approach. We make predictions using the QCD based…
We analyze the proton electromagnetic form factor ratio $R(Q^{2})=QF_2(Q^{2})/F_1(Q^{2})$ as a function of momentum transfer $Q^{2}$ within perturbative QCD. We find that the prediction for $R(Q^{2})$ at large momentum transfer $Q$ depends…
We consider the pion structure in the region of low and moderately high momentum transfers: at low $Q^2$, the pion is treated as a composite system of constituent quarks; at moderately high momentum transfers, $Q^2=10\div25\;GeV^2$, the…
We review the current understanding of heavy quark parton distributions in nucleons and their impact on deep inelastic scattering, collider physics, and other processes at high energies. The determination of the heavy-quark parton…
We review the latest information that is available about the parton distributions of the proton, paying particular attention to the determination of the gluon. We briefly describe the various processes that have been advocated to be a…
We present an improved determination of the strange quark and anti-quark parton distribution functions of the proton by means of a global QCD analysis that takes into account a comprehensive set of strangeness-sensitive measurements:…
In this high-$x$ region, both the flavour content and structure of the nucleon parton distribution functions remains relatively poorly known. New LHCb measurements of Z and charm jet associated production could indicate a valence-like…
The first measurements of the diffractive structure function $F_2^{D(3)}$ at HERA are discussed. A factorisable interpretation in which a partonic structure is assigned to the pomeron is investigated through QCD analyses in which both the…
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…
It is shown that the difference between the c-quark proton structure functions calculated in the k_T-factorization approach using different unintegrated gluon distribution functions is the same order as the difference between results…
We have developed a physical model for the non-perturbative x-shape of parton density functions in the proton, based on Gaussian fluctuations in momenta, and quantum fluctuations of the proton into meson-baryon pairs. The model describes…
Fully differential heavy quark contributions to the photon structure functions in deeply inelastic scattering are computed in next-to-leading order QCD, including both the direct and resolved contributions. A variety of distributions are…
We present a calculation of open charm quark production in diffractive deep inelastic electron-proton scattering in a perturbative QCD framework. The cross section is proportional to the square of the gluon density and explicitly displays…
In this article, we consider the ratio of structure functions for heavy quark pair production at low values of $x$. The importance of this ratio for charm and beauty pair production is examined according to the Hadron Electron Ring…
New results on charm quark production at HERA in an increased phase space in deep-inelastic scattering and photoproduction are discussed. Single & double-differential cross section distributions are compared to next-to-leading order QCD…
In the Framework of {\it{valon model}} we have calculated the parton distribution in a valon for both the polarized and unpolarized cases. These distributions are originated purely from the dressing of a valence quark in QCD and are common…
A model for the parton distributions in hadrons is derived from simple physical arguments leading to an analytical expression for the valence distributions. The sea parton distributions arise mainly from pions in hadronic fluctuations.…