Analysis of a High-Energy Cosmic-Ray Shower. I. Soft Component and Trident Process

Abstract

An analysis is presented of the soft component arising from a high energy nuclear shower (\ensuremath{\sim}3\ifmmode\times\else\texttimes\fi{}${10}^{13}$ ev) observed in stripped emulsion. The chief results obtained are: (1) The production ratio of neutral $\ensuremath{\pi}$ mesons to charged shower particles is 0.50\ifmmode\pm\else\textpm\fi{}0.11; (2) the lifetime of the neutral $\ensuremath{\pi}$ meson is found to be (${1}_{\ensuremath{-}0.5}^{+1}$) \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}14}$ sec; (3) the mean free path for direct electron pair production by high-energy electrons is found to be 4.4 and 1.1 radiation units for electrons in the energy intervals 1 to 10 Bev and 10 to 100 Bev, respectively.