Ratio of pions to protons and ratio of neutral to charged interacting particles at mountain altitude of 800 gm/cm²

Abstract

Using a combined set-up of a multiplate cloud chamber, an air Cerenkov counter and a total absorption spectrometer, the ratio of pions to protons not associated with large air showers has been determined to be 0·50 ± ·07 in the energy region 20-40 GeV at an altitude of 800 gm/cm². In the same energy region the ratio of neutral to charged particles is found to be 0.66 ± ·07. From the ratio of neutrons to protons deduced from these measurements (i.e., 0·99 ± ·11), it is concluded that most of the charge excess of nuclear active particles of energies > 20 GeV at mountain altitudes and sea-level is due to pions.