Study of Cosmic Ray Primary Mass Composition Using Monte Carlo Simulation and Statistical Methods

Tracing of cosmic ray origin and building a detailed and comprehensive idea about the sources are very much dependent on measurement of cosmic ray primary mass composition. High-energy cosmic rays produce extensive air showers in the earth's atmosphere, which in turn produce visible Cherenkov light. Distribution of Cherenkov photons over the observation level may be correlated with primary mass composition. This work aims to analyze the lateral density distribution of atmospheric Cherenkov light for various primary particles over a wide energy range (100 GeV-1 TeV) as well as to parameterize the obtained distributions using Monte Carlo simulation method. The simulations are carried out with CORSIKA (COsmic Ray SImulations for KAscade) 6.990 code. We have defined a new asymmetry parameter suitable for identifying primary mass composition. This parameter and the total number of Cherenkov photons are found to be sensitive in analyzing simulated data using a statistical method, called multiparametric topological analysis (MTA).