Extraction of Compton Form Factors from DVCS data

We present the results of a fitter code which aims at extracting Compton Form Factors (CFFs) from DVCS (Deep Virtual Compton Scattering) experimental data, in a largely model-independent way. CFFs are linked to GPDs (Generalized parton Distributions) and are the quantities which are directly measurable. The data that we have analyzed are from JLab and HERMES experiments. We obtain some first important constraints on the $H$ and $\tilde{H}$ CFFs. The kinematical dependences ($x_B$, $t$) of these CFFs provide some new insights on nucleon structure.Comment: 5 pages, 1 figure. Proceeding of ICHEP10 conference, July 22-28, 201

Deeply pseudoscalar meson electroproduction with CLAS and Generalized Parton Distributions

We discuss the recent data of exclusive $\pi^0$ (and $\pi^+$) electroproduction on the proton obtained by the CLAS collaboration at Jefferson Lab. It is observed that the cross sections, which have been decomposed in $\sigma_T +\epsilon\sigma_L$, $\sigma_{TT}$ and $\sigma_{LT}$ structure functions, are dominated by transverse amplitude contributions. The data can be interpreted in the Generalized Parton Distribution formalism provided that one includes helicity-flip transversity GPDs.Comment: 4 pages, 2 figures PANIC14 conference proceedin

Timelike Compton Scattering off the Proton: beam and/or target spin asymmetries

We present a sample of results of our work to be published soon on Timelike Compton scattering off the proton, in the framework of the Generalized Parton Distributions formalism.Comment: 2 figures, 4 pages, PANIC 2014 conference proceedin

Analysis of Deeply Virtual Compton Scattering Data at Jefferson Lab and Proton Tomography

The CLAS and Hall A collaborations at Jefferson Laboratory have recently released new results for the ep->ep{\gamma} reaction. We analyze these new data within the Generalized Parton Distribution formalism. Employing a fitter algorithm introduced and used in earlier works, we are able to extract from these data new constraints on the kinematical dependence of three Compton Form Factors. Based on experimental data, we subsequently extract the dependence of the proton charge radius on the quarks longitudinal momentum fraction.Comment: 25 pages, 26 figure

Generalized Parton Distributions and Deeply Virtual Compton Scattering

We present a method which allows to extract theoretical informations out of a limited set of experimental data and observables, forming up in general an under- constrained system. It has been applied to the field of nucleon structure, in the domain of Generalized Parton Distributions (GPDs). We take advantage of this review to remove a couple of approximations that we used in our previous works and update our results using the latest data published.Comment: 17 pages, 7 figures, to appear in JPhys

Discussion on the recent proton-DVCS results of Jefferson Lab

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 of polarized cross sections have been obtained. We modestly attempt a first "global" analysis of these three observables at a single $$,$$ and $$ kinematic point. We find that it is extremely challenging to describe simultaneously these data in the framework of a few Generalized Parton Distributions models.Comment: proceeding of the Photon2007 conference (International Conference on the Structure and Interactions of the Photon, Paris 9-13 July 2007