Mass composition of ultrahigh-energy cosmic rays, according to data from the Pierre Auger Collaboration: A statistical investigation using the Copula function

Abstract

The mass composition of cosmic rays with ultrahigh energies (2 × 10182–5 × 1019 eV) is studied using the publicly accessible data of the Pierre Auger Collaboration as of January 1, 2014. Employing tools for describing intrinsic relations inside multidimensional distribution (the Copula function) at 3 × 1018–3 × 1019 eV, the investigation reveals a mass composition weight of a complex nature.