Ein konsistentes mesontheoretisches Modell der Nukleon Antinukleon Wechselwirkung

A meson exchange model is presented for the N-$\overline{N}$ interaction. The elasticpart is taken to be the G-parity transform of the recent Bonn N-N potential, whichbeyond traditional one-boson-exchange diagrams also ta.kes into account explicit2$\pi$- and $\pi \rho$-exchange processes as well as virtual $\Delta$-exitations. It is defined interms of meson exchange over the whole ra.nge, i. e. no ad hoc parametrization ofthe inner part has to introduced.In a first step, a phenomenological, complex optical potential V$_{opt}$ has beenadded in order to globally a.ccount for N-$\overline{N}$ annihilntion. This simple N-$\overline{N}$ modelleads already to a good reproduction of the low- and medium-energy N-$\overline{N}$ data.In the next step, a theoretical annihilation model has been derived from nucleon,delta and hyperon ($\Lambda, \Sigma, \varUpsilon$*) exchange diagrams with 2-meson final states involving$\pi, \rho, \delta, \omega$, K and K* mesons. The corresponding meson-baryon couplingsare chosen consistently with former studies of the N-N and hyperon-nucleon system.Based on this microscopic annihilation model, agam using the G-parity transformof the Bonn potential as elastic part, the $\overline{p}$-p elastic as well as total crosssection data can be reproduced quantitatively, together with a shoulder in thep-parameter at low energies, suggested by experiment. In rontrast to the phenomenologicalannihilation model, the theoretkal model predicts several boundstates with relatively narrow widths ($\Gamma \le$ 30 Mev)