Elastic \rho' and \phi Meson Photo- and Electroproduction with Non-Resonant Background

The backgrounds due to the direct diffractive dissociation of the photon into the \pi^+\pi^- as well as $K^+K^-$ pairs to the "elastic" diffractive \rho ' and \phi $mesons production in electron-proton collisions are calculated. It is shown that the role of background and background-resonant interference contributions is very important in experimental distribution of$M_{\pi^+ \pi^-}$ in the \rho ' mass region. The amplitude for the background process is proportional to the \pi-meson - proton or K-meson - proton cross sections. Therefore, describing the HERA data, one can estimate \sigma (\pi p) and \sigma (Kp) at energies higher than the region of direct measurements.