π−pinteractions at 205 GeV/c: Multiplicities of charged and neutral particles; production of neutral particles

A study of 205-GeV/c ${\ensuremath{\pi}}^{\ensuremath{-}}p$ interactions has been made with a 48 800-picture exposure in the bare Fermilab 30-inch hydrogen bubble chamber. The average number of charged particles produced per inelastic interaction is 7.99\ifmmode\pm\else\textpm\fi{}0.06. The elastic cross section is 3.18\ifmmode\pm\else\textpm\fi{}0.13 mb and the total cross section is 24.19\ifmmode\pm\else\textpm\fi{}0.44 mb. The inclusive cross sections for neutral-particle production are: $\ensuremath{\sigma}(\ensuremath{\gamma})=171.3\ifmmode\pm\else\textpm\fi{}15.3$ mb, $\ensuremath{\sigma}({K}_{S}^{0})=3.64\ifmmode\pm\else\textpm\fi{}0.61$ mb ($xl0.3$), $\ensuremath{\sigma}(\ensuremath{\Lambda})=1.71\ifmmode\pm\else\textpm\fi{}0.34$ mb ($xl0.3$), and $\ensuremath{\sigma}(\overline{\ensuremath{\Lambda}})=0.59\ifmmode\pm\else\textpm\fi{}0.23$ mb ($xl0.1$). The average number of ${\ensuremath{\pi}}^{0}'\mathrm{s}$ produced per inelastic collision is consistent with a linear rise with the number of charged particles, and about equal to the number of produced ${\ensuremath{\pi}}^{\ensuremath{-}}$ or ${\ensuremath{\pi}}^{+}$. The average number of ${K}^{0}'\mathrm{s}$, $\ensuremath{\Lambda}'\mathrm{s}$, and $\overline{\ensuremath{\Lambda}}'\mathrm{s}$ is consistent with very little dependence on the number of charged particles. General characteristics of neutral-particle production are presented and compared with other experiments. For each topology the produced neutral energy is $\ensuremath{\sim}\frac{1}{3}$ of the incident energy.