Related papers: Parton distributions, form factors and Compton sca…
We relate ordinary and skewed parton distributions to soft overlap contributions to elastic form factors and large angle Compton scattering, using light-cone wave functions in a Fock state expansion of the nucleon. With a simple ansatz for…
The soft physics approach to Compton scattering at moderately large momentum transfer is reviewed. It will be argued that in that approach the Compton cross section as well as other exclusive observables exhibit approximate scaling in a…
We argue that at moderately large momentum transfer -t <10 GeV^2, hadronic form factors and wide-angle Compton scattering amplitudes are dominated by mechanism corresponding to overlap of soft wave functions. We show that the soft…
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…
The handbag contribution to Compton scattering at moderately large momentum transfer factorises into parton-photon subprocess amplitudes and new form factors representing 1/x-moments of skewed parton distributions. A detailed…
We derive light-cone sum rules for the electromagnetic nucleon form factors including the next-to-leading-order corrections for the contribution of twist-three and twist-four operators and a consistent treatment of the nucleon mass…
This work presents the first calculation in lattice QCD of three moments of spin-averaged and spin-polarized generalized parton distributions in the proton. It is shown that the slope of the associated generalized form factors decreases…
The central role of soft nucleon matrix elements in reactions of high energy electrons or real photons with nucleons is emphasized. These soft matrix elements are described in terms of skewed parton distributions. Their connections to…
The overlap representation of skewed parton distributions is discussed and applications to wide-angle Compton scattering and electroproduction of mesons are presented. The amplitudes for these processes factorise into parton-level…
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 continuum approach to the kaon and pion bound-state problems is used to reveal their electromagnetic structure. For both systems, when used with parton distribution amplitudes appropriate to the scale of the experiment, Standard Model…
Assuming the proton's light-cone wave function to be dominated by small parton virtualities and small intrinsic transverse momenta, we show that the electroproduction amplitudes at large momentum transfer factorize into parton-level…
We present a parameterization of the non-collinear (virtual) Compton scattering tensor in terms of form factors, in which the Lorentz tensor associated with each form factor possesses manifest electromagnetic gauge invariance. The main…
The recently proposed eight-component relativistic wave equation is applied to the scattering of a photon from a free electron (Compton scattering). It is found that in spite of the considerable difference in the structure of this equation…
The three-dimensional structure of nucleons (protons and neutrons) is embedded in so-called generalized parton distributions, which are accessible from deeply virtual Compton scattering. In this process, a high energy electron is scattered…
We present a simple empirical parameterization of the x- and t-dependence of generalized parton distributions at zero skewness, using forward parton distributions as input. A fit to experimental data for the Dirac, Pauli and axial form…
Nucleon elastic and transition form factors at high momentum transfer -t are treated in terms of generalized parton distributions in a two-body framework. In this framework the high -t dependence of the form factors give information about…
The contribution of the box and crossed two-pion-exchange diagrams to proton-proton scattering at 90$^{\circ}_{c.m.}$ is calculated in the laboratory momentum range up to 12 GeV/c. Relativistic form factors related to the nucleon and pion…
A recent proposal to measure the proton form factor by means of muon-proton scattering will use muons which are not ultrarelativistic (and also not nonrelativistic). The usual equations describing the scattering cross section use the…
I present an extraction of generalized parton distributions from selected data on the electromagnetic nucleon form factors. The extracted distributions can in particular be used to quantify the contribution to the proton spin from the total…