Classification of p- + p induced reactions

Annihilation cross sections of antiproton-proton into hadronic channels are studied and related experimental data are compiled. These channels constitute a high source of background to the annihilation reactions p-bar + p → l+ + l-, p-bar + p → l+ + l- + π0, used for the measurement of proton form factors in Time-like region. Pion multiplicity in final state is also analysed, since the 2 neutral or charged pion production is expected to be an important issue in the detection of the leptons pair.