Abstract
The production of single mesotrons in various materials was studied by means of an apparatus consisting of 46 Geiger-Mueller counters arranged in 10 different three-, four-, and fivefold coincidence sets. The producing layers consisted of different thicknesses of paraffin, iron, and lead. The results indicate that photons are the most probable agent for the production of the single mesotrons. The cross section for the mesotron production has been calculated for the various producing materials.