Exclusive diffractive production of real photons and vector mesons in $ep$ collisions has been studied at HERA in a wide kinematic range. Here we present and discuss a Regge-type model of real photon production (deeply virtual Compton scattering), as well as production of vector mesons treated on the same footing by using an extension of a factorized Regge-pole model proposed earlier. The model has been fitted to the HERA data. Despite the very small number of the free parameters, the model gives a satisfactory description of the experimental data, both for the total cross section as a function of the photon virtuality $Q^2$ or the energy $W$ in the center of mass of the ${\gamma }^{*}p$ system, and the differential cross sections as a function of the squared four-momentum transfer $t$ with fixed $Q^2$ and $W$.

• Received 10 January 2012

DOI:https://doi.org/10.1103/PhysRevD.85.054009