Related papers: Skewed Parton Distributions in Real and Virtual Co…
Generalized parton distributions describe the distribution of partons in the transverse plane. For transversely polarized quarks and/or nucleons, these impact parameter dependent parton distributions are not axially symmetric. These…
An overview on the new COMPASS II experimental programme is presented. The main topics include a study of Primakoff reactions, generalised parton distributions via deeply virtual Compton scattering and transverse momentum dependent…
The basic theoretical ideas of the handbag mechanism for wide-angle exclusive scattering reactions are discussed and, with regard to the present experimental program carried out at JLab, its application to Compton scattering is reviewed in…
We present the recent data issued from the Halls A and B of Jefferson Laboratory for the Deep Virtual Compton Scattering Process on the proton. An important set of data for beam spin asymmetries, unpolarized cross sections and differences…
We study the deeply virtual Compton scattering process with both twist-two and twist-three Compton form factors and present our cross-sections formulas with all polarization configurations. While the twist-three contributions are generally…
Different theoretical methods used for the description of diffractive processes in small-x deep inelastic scattering are reviewed. The semiclassical approach, where a partonic fluctuation of the incoming virtual photon scatters off a…
We consider the Generalized Parton Distributions for spin-1 nuclei in general and on the deuteron in particular. We use the impulse approximation to obtain a convolution model for them. Sum rules are used to check the validity of the…
We show how quark-hadron duality can emerge for valence spin averaged structure functions, and for the non-forward distributions of Deeply Virtual Compton Scattering. Novel factorisations of the non-forward amplitudes are proposed. Some…
The Weisberger relation, an exact statement of the parton model, elegantly relates a high-energy physics observable, the 1/x moment of parton distribution functions, to a nonperturbative low-energy observable: the dependence of the nucleon…
Generalised parton distributions are instrumental to study both the three-dimensional structure and the energy-momentum tensor of the nucleon, and motivate numerous experimental programmes involving hard exclusive measurements. Based on a…
This is the first of two papers in which we study real and virtual photon-proton scattering in a nonperturbative framework. We classify different contributions to this process and identify the leading contributions at high energies. We then…
We present the first measurement of the Timelike Compton Scattering process, $\gamma p\to p^\prime \gamma^* (\gamma^*\to e^+e^-) $, obtained with the CLAS12 detector at Jefferson Lab. The photon beam polarization and the decay lepton…
Results from a recent analysis of the zero-skewness generalized parton distributions (GPDs) for valence quarks are reviewed. The analysis bases on a physically motivated parameterization of the GPDs with a few free parameters adjusted to…
A detailed study of the heavy quark h=c,b,... contributions to deeply virtual Compton scattering is performed at both the amplitude and the cross section level, and their phenomenological relevance is discussed. For this purpose I calculate…
Recent progress on the parton distribution functions of the photon, both real and virtual, is briefly reviewed and experimental possibilities at HERA are discussed.
We study the timelike virtual Compton scattering process with a linearly polarized photon beam, in the generalized Bjorken scaling region and in the medium energy range which will be studied intensely at JLab12 experiments. We define new…
We study the deeply virtual Compton scattering cross-section in twist-two generalized parton distribution (GPD) approximation, and show that different choices of light-cone vectors and gauges for the final photon polarization will lead to…
The generalized parton distributions (GPDs) of the meson and nucleon at small and large values of the momentum transfer were determined on the basis of the comparative analysis of different sets of experimental data of electromagnetic form…
Wide-angle Compton scattering (WACS) is discussed within the handbag approach in which the amplitudes are given by products of hard subprocess amplitudes and form factors, specific to Compton scattering, which represent 1/x-moments of…
We estimate the two-photon exchange contribution to elastic electron-proton scattering at large momentum transfer by using a quark-parton representation of virtual Compton scattering. We thus can relate the two-photon exchange amplitude to…