π−pInteractions at 10 GeV/cwith Four Charged Secondaries

Abstract

About 800 ${\pi }^{-}p$ interactions with four charged secondaries produced by 10.25-GeV/c negative pions in the 81-cm Saclay hydrogen bubble chamber have been analyzed. The cross sections for the various reactions, including the production of $N^{*}$, $\rho$, and $\omega$ are given in Tables I and III. The c.m.-system angular and momentum distributions are discussed; the nucleons are strongly peaked backward whereas the pions, especially the ${\pi }^{-}$, go predominantly forward. Values for the average transverse momentum of the various secondary particles have been determined. From plots of the average transverse momentum versus the c.m.-system longitudinal momentum correlations between the momentum $p^{*}$ and the scattering angle ${\Theta }^{*}$ can be seen; it is found that $p^{*}$ is essentially proportional to the inverse of ${sin\Theta }^{*}$. The occurrence of resonant states has been investigated. Production of ${\rho }^0$ seems very important at this energy in the $p{\pi }^{-}{\pi }^{+}{\pi }^{-}$ final state. Production of $N^{*++}$ is relatively more important in final states involving additional pions and a proton.