Two-meson doorway model of low energy antiproton-proton annihilation

We investigate a semiclassical model for panti p annihilation into any number of pions and kaons at antiproton lab momenta plab<3 GeV/c, based on the hypothesis of two-meson doorway states as intermediate channels in the annihilation process. All relevant selection rules are incorporated. We find that with baryon radii of about 0.6 fm, the energy dependence of partial cross sections in all important annihilation channels can be reproduced successfully. Angular distributions for panti p→π+π- and K+K- can also be described, provided one admits a substantial s-wave suppression in this model. (orig.)