Related papers: A Check-up for the Statistical Parton Model
The Fourier transform of generalized parton distribution functions at xi=0 describes the distribution of partons in the transverse plane. The physical significance of these impact parameter dependent parton distribution functions is…
The production rates of lepton-photon and dimuon pairs at the HERA collider and the HERMES experiment are evaluated in the leading order equivalent photon approximation. It is shown that the production rates are sufficient to facilitate the…
In this paper polarized valon distribution is derived from unpolarized valon distribution. In driving polarized valon distribution some unknown parameters exist which must be determined by fitting to experimental data. Here we have used…
A recent proposal seeks to explain the anomaly in the HERA high-Q^2 neutral current e^+p data by modifying the parton distribution functions at moderate-to-high-x and large Q^2. We investigate the consequences of this proposal for the HERA…
Longitudinal polarisation of the lepton beam is a key ingredient to the success of the world's unique e\pmp ring collider HERA. This article aims at providing a brief introduction to the physics motivation for deep-inelastic scattering of…
We discuss the determination of polarized parton distributions from a next-to-leading order analysis of recent experimental data. We extract the first moment of the polarized quark and gluon distribution and assess the corresponding…
We study $\rho$ meson unpolarized generalized parton distributions based on a light-front constituent quark model where the quark-antiquark-meson vertex is constructed under the symmetric loop momentum convention. The form factors and some…
We recall how parton distributions are constructed in a statistical physical picture of the nucleon. The chiral properties of QCD lead to strong relations between quarks and antiquarks distributions and the importance of the Pauli exclusion…
A quantum statistical parametrization of parton distributions has been considered. In this framework, the exclusion Pauli principle connects the violation of the Gottfried sum rule with the Ellis and Jaffe one, and implies a defect in the…
Quantum statistical distributions for the partons provide a fair description of deep inelastic scattering data at $Q^2 = 3$ and $10 (GeV/c)^2$. The study of the polarized structure functions seems to suggest an alternative possible solution…
For an unpolarized target, the generalized parton distribution $H_q(x,0,t)$ is related to the distribution of partons in impact parameter space. The transverse distortion of this distribution for a transversely polarized target is described…
Inclusive neutral and charged current cross sections and structure functions measured at HERA-I are briefly reviewed. The impact of these measurements on parton density functions is discussed. The emphasis is put on the high x region. A…
High Q^2 NC and CC cross-sections as measured at HERA can give information on two distinct areas of current interest. Firstly, supposing that all the electroweak parameters are well known, these cross-sections may be used to give…
Diffractive parton distributions of the proton are determined from fits to diffractive data from HERA. In addition to the twist--2 contribution, the twist--4 contribution from longitudinally polarised virtual photons is considered, which is…
We discuss polarized proton-positron scattering in the context of the excess of large $Q^2$ events at HERA. We define and estimate a polarized asymmetry to examine two scenarios, the contact interaction and the stop scenario with broken…
The HERA diffractive structure function data are interpreted in terms of `diffractive parton distributions' which satisfy DGLAP evolution. These distributions are modeled assuming that the scattering takes place off a colour singlet…
We calculated the polarized parton distributions in leading order approximation in QCD from valon model. Polarized structure function of the nucleon are analyzed in the polarized valon model in which a nucleon is assumed to be a bound state…
A review of the present knowledge on polarized parton distributions is given. The effects of perturbative evolution on these distributions are discussed qualitatively and a comparison of various recent parametrizations is made.
A simple picture of the constituent quark as a composite system of point-like partons is used to construct the unpolarized and polarized parton distributions by a convolution between constituent quark momentum distributions and constituent…
We discuss the statistical properties of parton distributions within the framework of the NNPDF methodology. We present various tests of statistical consistency, in particular that the distribution of results does not depend on the…