A study on the lateral distribution of Cherenkov light in extensive air showers

Abstract

The dependence of the lateral distribution of Cherenkov light in simulated extensive air showers to the energy and the mass of the primary cosmic rays has been studied. It has been shown that a previous claim about mass independent proportionality of shower energy to the total Cherenkov photon number is not valid in energies below EEAS ~ 1014 eV. We have found that the core distance of the so called hump in the lateral distribution of Cherenkov light in gamma ray initiated showers is independent from shower energy. The hump disappears in showers with EEAS ≳ 1014 eV. Finally, a simple model for the lateral Cherenkov light lateral distribution has been proposed, which can be fitted to all types of cosmic ray showers. The fit parameters seem to be promising for primary cosmic ray mass discrimination.