Study on the Lateral Density Distributions of Cherenkov Photons Generated by Different Particle Showers

Cosmic rays, which are high-energy particles arriving from outer space, serve as important probes for examining the composition of extrasolar matter and the dynamics of high-energy astrophysical phenomena. Studying the extensive air showers initiated by primary γ-rays, protons, and iron nuclei provides insight into the radiation processes that drive cosmic evolution, the origins of matter, and energetic astrophysical events. In this work, Monte Carlo simulations were employed to model the development of air showers produced by primary particles of varying energies and zenith angles as they enter Earth's atmosphere. The analysis focused on the lateral density distributions of Cherenkov photons generated by the secondary particles at an observation altitude of 4300 m. The results indicate that the radial dependence on the radius variable R of the Cherenkov photon density ρ can be represented by , its dependence on the zenith angle θ by , and its dependence on primary energy E by . Notably, γ-ray-induced showers exhibit a characteristic hump in their lateral photon density profile. These findings improve agreement with experimental measurements of extensive air showers and support the estimation of detector responses, thereby enhancing understanding of the underlying shower development processes.