Related papers: Low x_{bj} DIS, QCD and Generalized Vector Dominan…
We study in the framework of collinear QCD factorization the photoproduction of a $\gamma\,\pi$ pair with a large invariant mass and a small transverse momentum, as a new way to access generalized parton distributions. In the kinematics of…
We examine the total cross section of virtual photons on protons, $\sigma_{\gamma^* p}(W^2,Q^2)$, at low $x \cong Q^2/W^2 \ll 1$ and its connection with ``elastic'' diffractive production $\gamma^*_{T,L}p \to X^{J=1}_{T,L} p$ in the…
We study the leading-twist unpolarized generalized parton distributions (GPDs) of light and heavy vector mesons, i.e., the $\rho$, $J/\psi$ and $\Upsilon$, at zero skewness. An ansatz incorporating the zero mode contribution is introduced…
This work reviews the recent developments in the field of Generalized Parton Distributions (GPDs) and Deeply virtual Compton scattering in the valence region, which aim at extracting the quark structure of the nucleon. We discuss the…
Virtual photons have both the transverse and longitudinal polarization. In the inclusive DIS the impact of longitudinal photons, quantified by R=sigmaL/\igmaT sim 0.2, is marginal, but in diffractive DIS with excitation of small mass…
The link between the nucleon generalized parton distributions and the non-diagonal one-body density matrix in momentum space is studied. Attention is focussed on the region where quark generalized parton distributions (GPD's) describe…
Given a graph $G$, an integer $k\geq 0$, and a non-negative integral function $f:V(G) \rightarrow \mathcal{N}$, the Vector Domination problem asks whether a set $S$ of vertices, of cardinality $k$ or less, exists in $G$ so that every vertex…
The processes $e^+e^-\to \pi^+\pi^-, \omega\pi^0, \eta\pi^+\pi^-, K^+K^-, \pi^+\pi^-\pi^0$ are described simultaneously in the frame of the Generalized Vector Dominance Model (GVDM) allowing model error. The data do not contradict the…
We define generalized vector fields, and contraction and Lie derivatives with respect to them. Generalized commutators are also defined.
We demonstrate how the virtual photoproduction of vector mesons on nuclei scans the wave function of vector mesons from the large non-perturbative transverse size $\rho \sim R_{V}$ down to the small perturbative size $\rho \sim…
The study of $J/\psi$ photoproduction at low energies has consequences for the understanding of multiple aspects of nonperturbative QCD, ranging from mechanical properties of the proton, to the binding inside nuclei, and the existence of…
The chiral-odd generalized parton distribution (GPD), or transversity GPD, of the nucleon can be accessed experimentally through the photo- or electroproduction of two vector mesons on a polarized nucleon target, \gamma^(*) N --> \rho_1…
The integrated cross section for the incoherent photoproduction of vector mesons on nuclei $\gamma^* A \to VX$, $X\not=A$, is calculated within Glauber theory and as a function of the photon energy. The inverse of the longitudinal momentum…
We investigate the photon structure functions via the photon-photon and photon-vector meson scattering within the framework of holographic QCD, focusing on the small Bjorken $x$ region and assuming that the Pomeron exchange dominates. The…
Rho photoproduction on complex nuclei is re-examined using a generalised vector dominance model which succesfully predicts the observed nuclear shadowing in real photoabsorption and deep inelastic scattering. This model is shown to give a…
Phase transitions with spontaneous symmetry breaking and vector order parameter are considered in multidimensional theory of general relativity. Covariant equations, describing the gravitational properties of topological defects, are…
I review the modern status of QCD theory of diffractive vector meson production with the focus on shrinkage of photons with Q2 and (Q2+mV2)$scaling, j-plane properties of the QCD pomeron and Regge shrinkage of diffraction cone, $s$-channel…
While the chiral-even content of the nucleon is better and better studied, the chiral-odd transversity generalized parton distributions (GPDs) remain almost unknown. These GPDs can be accessed experimentally through the exclusive…
Vector fields with components which are generalized zero-forms are constructed. Inner products with generalized forms, Lie derivatives and Lie brackets are computed. The results are shown to generalize previously reported results for…
We provide convex body domination results for the generalized vector-valued commutator of those operators that admit specific forms of convex body domination themselves. We also prove some strong type estimates and other consequences of…