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Role of the non-resonant background in the $ρ^0$-meson diffractive electro- and photoproproduction

M. G. Ryskin·Yu. M. Shabelski
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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. The amplitude for the background process $γp \to π^+ π^- p$ is proportional to the $π$-meson - proton cross section. Therefore, describing the HERA data, we can estimate $σ(πp)$ at energy $s_{πp}\sim (2 - 3) \times 10^{3}$ GeV$^2$ that is considerably higher the existing data. At large $Q^2$ the interference between resonant and non-resonant $π^+ π^-$ production leads also to the more slow increase of the $σ^L/σ^T$ ratio with the mass of the $2π$ (i.e. $ρ^0$-meson) state.

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M. G. Ryskin, Yu. M. Shabelski. 1997-01-29. Role of the non-resonant background in the $ρ^0$-meson diffractive electro- and photoproproduction. https://arxiv.org/abs/hep-ph/9701407

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