Coherent meson production in antinucleon annihilation on nuclei

A phenomenological optical potential for antinucleon-nucleon (N?N) interaction in an energy range of 1 to 15 GeV is presented in an eikonal model. In addition to the discussion of the strength and energy dependence, the potential is used to describe initial state interactions for coherent meson production on nuclei. To describe nuclear matter effects, Hartree-Fock Bogoliobuv (HFB) densities are used. As a first step we calculate the production of two mesons, namely pions. To cover the large energy range, the final state pion-nucleus ( π A) interaction is improved by adding resonances beyond the Δ resonance to a Kisslinger-type ansatz. Results for N?N and π A cross sections are presented.