Related papers: Generalized parton distributions and wide-angle ex…
We investigate the exclusive photoproduction of a heavy timelike photon which decays into a lepton pair, gamma p -> l+ l- p. This can be seen as the analog of deeply virtual Compton scattering, and we argue that the two processes are…
Exclusive proton-antiproton annihilation into two photons at large s (~10 GeV^2) and |t|,|u| ~ s can be described by a generalized parton picture analogous to the 'soft mechanism' in wide-angle real Compton scattering. The two photons are…
The main contribution to hard elastic scattering comes from components of wave functions of colliding hadrons that contain minimum number of partons. We discuss this mechanism in regge and parton approaches and estimate the probabilities…
An introductory to generalized parton distributions is given which emphasizes their spectral property and its uses as well as the equivalence of various GPD representations. Furthermore, the status of the theory and phenomenology of hard…
Exclusive hadron production processes in photon-photon collisions provide important tests of QCD at the amplitude level, particularly as measures of hadron distribution amplitudes and skewed parton distributions. The determination of the…
A few examples of quickly developing field of double parton scattering are discussed. We present arguments that the production of two pairs of charm quark-antiquark is the golden reaction to study the double parton scattering effects. We…
In the framework of the QCD parton model, we study unpolarized scattering of high energy real photons from a proton target into lepton pairs and a system of hadrons. For a given parametrization of parton distributions in the proton, we…
Virtual photons have proven to be very efficient probes of the hadronic structure, mostly through deep inelastic scattering and related processes. The advent of high luminosity lepton beams has allowed to enlarge the studied processes to…
Exclusive reactions induced at high momentum transfer in few body systems provide us with an original way to study the production and propagation of hadrons in cold nuclear matter. In very well defined parts of the phase space, the reaction…
We analyze light meson electroproduction within the handbag model, where the amplitude factorizes into Generelized Parton Distributions (GPDs) and a hard scattering part. The cross sections and spin asymmetries for various vector and…
We introduce generalized quark and gluon distributions in the deuteron, which can be measured in exclusive processes like deeply virtual Compton scattering and meson electroproduction. We discuss the basic properties of these distributions,…
Hard exclusive reactions are the tool to learn about generalized parton distributions, which provide a more complete parametrization of the nucleon than the ordinary parton distribution functions. Recent measurements by the HERMES…
It is shown that the contribution from double parton scattering to the inclusive double heavy meson yield is quite comparable with the usually considered mechanism of their production at the LHC energy. For some pairs of heavy flavored…
We give a brief overview on the theory and phenomenology of generalized parton distributions (GPDs), including the recently developed framework of single-diffractive hard exclusive process for matching GPDs to experimental observables. We…
Several hard exclusive scattering processes admit a description in terms of generalized parton distributions and perturbative hard-scattering kernels. Both the physical amplitude and the hard-scattering kernels fulfill dispersion relations.…
We present a short overview over the different contributions to high energy photon photon scattering and explore the possibilities of tuning the sizes of the scattered objects by changing the virtuality of the photons. We compare the…
Exclusive $\gamma\gamma \to$ hadron pairs are among the most fundamental processes in QCD, providing a detailed examination of Compton scattering in the crossed channel. In the high momentum transfer domain $(s,t, {large},\theta_{cm}$ for…
Exclusive photoproduction of dileptons, gamma p ->l+ l- p, will be measured in ultraperipheral collisions at LHC. The mechanism where the lepton pair comes from a heavy timelike photon radiated from a quark interferes with the pure QED…
It is generally assumed that due to factorization of long- and short-distance dynamics perturbative QCD can be applied to exclusive hadronic reactions at large momentum transfers. Within such a perturbative approach diquarks turn out to be…
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…