Intermittent behaviour in small CORSIKA showers

Abstract

In this work we are concerned with the quantitative study of correlations between charged particles: electrons/positrons and muons in small Extensive Air Showers. By “small”, we mean showers that are initiated by primary protons with energies of up to ∼1 TeV. We study the strength of these correlations with the help of the CORSIKA simulation program. The results show the ‘intermittent’ behaviour of the density distributions. This is particularly evident for the electron component of very small showers with primary particle energies on the order of 100 GeV or less, where the shower consists of up to ten or so charged particles. For shower muons, the correlations are significantly smaller, and it is important to determine the values of the residual correlations for experiments that are shielded from the electron component. Detectors in surface shower arrays that measure both hard and soft component particles are by design sensitive to a superposition of strong electron correlations and weak or even non-existent correlations in the muon component. This folding is not trivial, and we show how it ends up getting folded. This is interesting in itself, and the specific values of the scaled factor moments allow us to estimate the possible effects of these large non-Poisson fluctuations. This may be relevant to the analysis of data from small shower arrays and other atypical experimental facilities where cosmic ray particles are an unwanted background.