Observation of the Production of Short-Lived Particles in a High-Resolution Streamer-Chamber Experiment

Abstract

Short-lived particles produced in association with muons have been observed in the interactions of 350-GeV/c protons with neon in a high-resolution streamer chamber. The characteristics of these events are consistent with the expected properties of charmed particles if the average lifetime lies between ${10}^{\ensuremath{-}13}$ and 2\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}12}$ sec. With the assumption that the observed events are mainly ${D}^{\ifmmode\pm\else\textpm\fi{}}$ mesons with lifetimes of approximately ${10}^{\ensuremath{-}12}$ sec, the production cross section is estimated to lie between 20 and 50 \ensuremath{\mu}b per nucleon.