High Energy Gamma-Rays in the Atmosphere and Muons Underground and Underwater

Abstract

The behaviour of high energy nuclear active particles, ')-rays, muons and neutrinos. in the atmosphere aru:l underground is analyzed under the light of recent experimental results obtained by several groups in Japan. Through our analysis the following conclusions are obtained. (1) The attenuation length of theN-component of energies above a few TeV is about 110 g cm-, as derived from the altitude variations of the ')-ray flux and the nuclear interaction frequency. (2) The break in the 7-ray spectrum can be attributed to that in the primary spectrum, implying that the features of nuclear interactions do not appreciably change as energy increases as high as 100 TeV. (3) The intensity-depth relation of the muon flux is found to be consistent with the ')-ray spectrum by taking proper account of the range fluctuations of muons. ( 4) The ratio of kaons to pions at high energies is consistent with that observed in jet showers. The present paper is such a review article that contains a summary of experimental data, the method of dealing with cascade showers, the mathematical treatment of the range fluctuations and the neutrino fluxes expected.