Antiproton-proton interactions at 5·7 Gev/c I. Nonannihilation channels

Abstract

We present an analysis of nonannihilation channels in four-pronged$\bar pp$ interactions at 5·68 GeV/c. The transverse momenta and azimuthal angles distributions of nucléons and π-mesons are compared with phase space. No essential influence of$\Delta ^{ + + } /\overline {\Delta ^{ + + } }$ production on azimuthal correlation has been found. The seen difference of azimuthal angle distributions for like and unlike charged pions in annihilations appears to be more pronounced for small transverse momenta and for small transverse masses. For 10971 events of the reaction ¯pp→¯ppπ⁻π⁺ we present cross sections for$\Delta ^{ + + } ,\overline {\Delta ^{ + + } } ,\Delta ^0 ,\overline {\Delta ^0 }$ production and differential cross sections. The reaction is dominated by the strong quasi-two-body channel$\bar pp \to \overline {\Delta ^{ + + } } \Delta ^{ + + }$ with cross section (1·66 ±±0·10) mb. We study in detail the production mechanism of this channel in terms of the absorption model.