${\sigma }_L\mathrm{/}{\sigma }_T$ in the ${\rho }^0$ - meson diffractive electroproproduction

The background due to the direct diffractive dissociation of the photon into the ${\pi }^{+}{\pi }^{-}$-pair to the “elastic” diffractive ${\rho }^0$-meson production in electron-proton collisions is calculated. At large $Q^2$ the interference between resonant and non-resonant ${\pi }^{+}{\pi }^{-}$ production changes the ${\sigma }^L\mathrm{/}{\sigma }^T$ ratio with the mass of the $2\pi$ (i.e. ${\rho }^0$-meson) state.