Multifractal characterisation of fluctuations in simulated Extensive Air Showers

High-energy interactions of gamma rays and protons with the Earth atmospher e have been simulated by means of the CORSIKA Monte Carlo code, and the sec ondary-particle density distributions in the resulting extensive air shower s, at ground level, have been studied. It is shown that the fluctuations of the density distributions as a function of the polar angle have features t ypical of a 1/f noise. The sample is then analysed in order to study its sc aling behaviour and we find that it can be parametrized by means of a unive rsal multifractal approach.