A study of the cores of air showers in the size range 104 to 107 particles

Abstract

Results from the Sydney 64-scintillator array are reported. The array now uses logarithmic amplifiers with a range from 1 to 300 000 particles per square meter. This allows us to detect both higher and lower central densities than was previously possible. Further observations and comparison with Monte Carlo calculations confirm the previous result that air showers in the size range 104 to 5 × 105 particles are due to cosmic-ray primaries with much the same charge spectrum as at 1011 eV total energy.Showers of size greater than 106 particles seem mostly to be multicored (in agreement with previous results). The apparent transverse momentum is high and increases with shower size. The quantity rpL/n, which is a measure of the mean transverse momentum in very high energy interactions, is always greater than 1 GeV/c and increases with shower size. The existence and nature of a possible superstrong interaction are briefly discussed.