抄録
Nine nuclear interactions, observed in a stack of nuclear emulsions, are analyzed in the center-of-mass system. The angular distribution of secondary particles is isotropic for primary energy, Ep, up to several tens of GeV. The distribution shows an appreciable forward-backward collimation for Ep\simeq200 GeV. The average energy of a produced pion is 0.48 GeV. The number of pions at the total energy less than 0.21 GeV is fairly small. The energy spectrum can be represented by a power law with exponent −2 for the middle region of pion energy. An inspection of experimental results so far published shows that the corresponding exponent for Ep\gtrsim1400 GeV is −1. The mechanism of multiple production probably changes between 200 and 1400 GeV, and does not differ markedly from severel GeV to 200 GeV.
