Cosmic radiation variations and meson disintegration

Abstract
Measurements of cosmic radiation were made during five years at the Cómmonwealth Observatory, Canberra, using an ionization chamber screened by 10 cm. of lead. The results are examined here to determine whether the observed magnitudes and variations of the temperature effect, and the barometer effect, may be accounted for by the theory of meson decay in the atmosphere. Satisfactory agreement is found to exist between the value of the rest life of the meson ז 0 , as obtained by five different methods of examining the meteorological variations of cosmic rays. The absorption coefficient of mesons in dense matter, μ , may also be obtained from the meteorological variations and is in agreement with a more directly determined value. Values of ז 0 are in the range 2 to 4 μ sec. and μ in the range 0∙0014 and 0∙0021 cm. –2 g. –1 .