Features of muon arrival time distributions of high energy EAS at large distances from the shower axis

Abstract

In view of the current efforts to extend the KASCADE experiment (KASCADE-Grande) for observations of extensive air showers (EAS) of primary energies up to 1 × 1018 eV, the features of muon arrival time distributions and their correlations with other observable EAS quantities have been scrutinized on the basis of high energy EAS, simulated with the Monte Carlo code CORSIKA and using in general the QGSJET model as generator. Methodically, various correlations of adequately defined arrival time parameters with other EAS parameters have been investigated by invoking non-parametric methods for the analysis of multivariate distributions, studying the classification and misclassification probabilities of various observable sets. It turns out that adding the arrival time information and the multiplicity of muons spanning the observed time distributions has distinct effects improving the mass discrimination. A further outcome of the studies is the feature that for the considered ranges of primary energies and distances from the shower axis the discrimination power of global arrival time distributions referring to the arrival time of the shower core is only marginally enhanced as compared to local distributions referring to the arrival of the locally first muon.