Related papers: The Charm Quark Contribution to the Proton Structu…
Preliminary results on a measurement of the proton structure function F_2 are reported for momentum transfers squared Q^2 between 1.5~GeV^2 and 5000 GeV^2 and for Bjorken x between 5.10^{-5} and 0.32 using data collected by the HERA…
Expectations for the momentum distribution of nonperturbative charm and bottom quarks in the proton are derived from a variety of models for the Fock space wave function on the light cone.
Recent data on the (inelastic) Nachtmann moments of the unpolarized proton structure function F2p, obtained at low momentum transfer with the CLAS detector at Jefferson Lab, have been interpreted in terms of the dominance of the elastic…
A model for the longitudinal structure function $F_L$ in the region of low $x$ and low $Q^2$ is discussed. It is constructed using the $k_T$ factorization theorem and a photon-gluon fusion mechanism suitably extrapolated to the region of…
We study the possibility of intrinsic (non-perturbative) charm in parton distribution functions (PDF) of the proton, within the context of the CT10 next-to-next-to-leading order (NNLO) global analysis. Three models for the intrinsic charm…
At a low resolution scale with $Q^2={\mu}^2$ corresponding to the nucleon bound state; deep inelastic unpolarized structure functions $F_1(x,{\mu}^2)$ and $F_2(x,{\mu}^2)$ are derived with correct support using the symmetric part of the…
The proton structure function in the diffraction region of small Bjorken-$x$ and $10 {\rm GeV}^2 \le Q^2 \le 100 {\rm GeV}^2$ behaves as $F_2 (x, Q^2) = F_2 (W^2) = f_0 \cdot (W^2)^{C_2}$, where $x = Q^2 / W^2$. The exponent $C_2$ of the…
Parton distribution functions (DFs) are defining expressions of hadron structure. Exploiting the role of effective charges in quantum chromodynamics, an algebraic scheme is described which, given any hadron's valence parton DFs at the…
New results from the H1 and ZEUS collaborations on the measurement of cross-sections at very high Q^2 (up to 25000 GeV^2) and on the proton structure function F_2(x,Q^2) for momentum transfers squared Q^2 >= 1.5 GeV^2 and Bjorken x >= 3.5…
We describe the determination of the longitudinal structure function $F_{L}$ at NLO and NNLO approximations, using Laplace transform techniques, into the parametrization of $F_{2}(x,Q^{2})$ and its derivative with respect to $\ln{Q^{2}}$ at…
We check the impact of the gluon distribution due to the number of active flavor employed in the calculation of heavy-quark deep-inelastic scattering (DIS) electro-production on the reduced cross section and structure functions determined…
The $F_{2}$, $F_{G}$, $R=F_{L}/F_{T}$ proton structure functions are derived in the QCD dipole picture of BFKL dynamics. We get a three parameter fit describing the 1994 H1 proton structure function $F_{2}$ data in the low $x$, moderate…
We have utilized the concept of valon model to calculate the spin structure functions of proton, neutron and deuteron. The valon structure itself is universal and arises from the perturbative dressing of the valence quark in QCD. Our…
Deep-inelastic production of heavy quarks at HERA, especially charm, is an excellent signal to measure the gluon distribution in the proton at small $x$ values. By measuring various differential distributions of the heavy quarks this…
We investigate the prospects for measuring the strange quark distribution function of the proton in associated $W$ plus charm quark production at the Tevatron. The $W+c$ quark signal produced by strange quark -- gluon fusion, $sg\rightarrow…
The gluon distribution is dominated by the hard pomeron at small $x$ and all $Q^2$, with no soft-pomeron contribution. This describes well not only the DGLAP evolution of the hard-pomeron part of $F_2(x,Q^2)$, but also charm photoproduction…
The recent measurement of the differential $ \gamma+c $-jet cross section, performed at the Tevatron collider in Run II by the D0 collaboration, is studied in a next-to-leading order (NLO) global QCD analysis to assess its impact on the…
We construct a simple two-phase model of the nucleon structure functions valid for both small and large Q^2 and in the broad range of Bjorken x. The model incorporates hadron dominance at small x and Q^2 and parton model at large Q^2. The…
We employ the maximum entropy method to extract the valence quark distributions of the neutron at a low scale, \( Q_0^2 \). At this initial scale, the neutron is defined to contain only three valence quarks, with no contributions from sea…
A fit is made to the data for the proton structure function up to Q^2=10 GeV^2, including the real gamma p total cross-section. It is economical and simple, and its form is motivated by physical principles. It is extrapolated down to very…