Proton-antiproton scattering and annihilation into two mesons

We present a combined semiphenomenological analysis of the low-energy pp annihilation into two mesons and of the pp scattering processes which enter into the description of the initial state before two-meson annihilation. Angular distributions for pp → π⁺ π^- and pp → K⁺K^- are investigated with the aim of studying the relative importance of quark rearrangement and quark-antiquark annihilation mechanisms. Such simple quark models describe basic features of the pp → π⁺ π^- reaction, but fail to reproduce details of the pp → K⁺K^- angular distributions. Possible improvements are discussed.