$σ_L/σ_T$ in the $ρ^0$ - meson diffractive electroproproduction

Abstract

The background due to the direct diffractive dissociation of the photon into the $π^+π^-$-pair to the "elastic" diffractive $ρ^0$-meson production in electron-proton collisions is calculated. At large $Q^2$ the interference between resonant and non-resonant $π^+ π^-$ production changes the $σ^L/σ^T$ ratio with the mass of the $2π$ (i.e. $ρ^0$-meson) state.