Reactionsp¯p→pπ±Xand a comparison with leptoproduction and the quark-parton model

We have studied the inclusive reactions $\overline{p}p\to p{\pi }^{\pm }X$ at 8.9 GeV/c and compared them to the lepton-induced processes $e^{-}p\to e^{-}{\pi }^{\pm }X$ and the photoproduction reactions $\gamma p\to {\pi }^{\pm }X$. The naive quark-parton model is found to be quite successful in interpreting the results. The distribution of charge in the current-fragmentation region is consistent with production of ${\pi }^{\pm }$ via absorption of the current by fractionally charged valence antiquarks of the antiproton.