We propose generation of narrow-bandwidth GeV photons, gamma-rays, via Compton scattering of hard X-ray photons in X-ray free-electron laser oscillators [1]. The gamma-rays have a narrow-bandwidth spectrumwith a sharp peak, ∼0.1% (FWHM), due to the nature of Compton scattering in relativistic regime. Such gamma-rays will be a unique probe for studying hadron physics. In this paper, we discuss d...

Exclusive photoproduction of dileptons, γp → `+`− 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 process γγ → `+`−. As an analog of deeply virtual Compton scattering, this timelike Compton scattering is a way to study generalized parton distributions in the nucleo...

We study Real and Deeply Virtual Compton Scattering in a model based on Regge trajectories and two-gluon exchange. In the kinematic regime of current experiments, the hadronic component of the outgoing real photon plays a major role. We analyze the spin structure of Compton scattering at large momentum transfer and give predictions for several spin asymmetries. In the DVCS channel, a fairly goo...

Exclusive two-photon reactions such as Compton scattering at large angles, deeply virtual Compton scattering, and hadron production in photon-photon collisions provide important tests of QCD at the amplitude level, particularly as measures of hadron distribution amplitudes and skewed parton distributions. Invited talk presented at Photon 2000 Ambleside, England August 26–31, 2000 ∗Work supporte...

Compton scattering by pion: there is no room for the off–shell effects. Abstract We show that the off–shell contributions in Compton scattering by pion may exist only in the single exchange diagrams. These contributions are canceled completely in the total gauge–invariant amplitude as it confirmed by one–loop calculations. It explains, in particular, some results of the chiral pertubation theor...

A rotating NaI(TI) scintillator detector and a collimated Cs 137 source producing gamma rays with an energy of 662 keV scattered incoherently by aluminum (Al) and copper (Cu) scatterers through the angles from 0 to 120° are used to study Compton scattering. The Compton scattering effect is investigated and found that the energy of scattered gamma ray decreases as the scattering angles increases...

In a previous paper virtual Compton scattering off the nucleon has been investigated in the one–loop approximation of the linear sigma model in order to determine the 3 scalar generalized polarizabilities. We have now extended this work and calculated the 7 vector polarizabilities showing up in the spin–dependent amplitude of virtual Compton scattering. The results fulfill 3 model–independent c...

We give a complete representation of virtual Compton scattering γp → γp at large initial photon virtuality Q and small momentum transfer squared t in terms of the light-cone wavefunctions of the target proton. We verify the identities between the skewed parton distributions H(x, ζ, t) and E(x, ζ, t) which appear in deeply virtual Compton scattering and the corresponding integrands of the Dirac ...

We discuss the experimental issues confronting measurements of the Virtual Compton Scattering (VCS) reaction ep → epγ with electron beam energies 6–30 GeV. We specifically address the kinematics of Deeply Virtual Compton Scattering (Deep Inelastic Scattering, with coincident detection of the exclusive real photon nearly parallel to the virtual photon direction) and large transverse momentum VCS...