Selecting gamma-ray showers from hadronic background using lateral shower age of EAS

A Monte Carlo (MC) simulation study has been carried out, aimed at identifying and rejecting the background component, constituted by hadronic cosmic rays, from γ -ray primaries in the multi-TeV region. In this work, our main focus is to discuss the possible role of the local age parameter (LAP) of cosmic ray extensive air shower (EAS) for separating γ -ray initiated showers from hadron initiated showers. Assigning a mean LAP to each EAS event, we found that the parameter might be useful for selecting γ -ray showers from hadron initiated showers in ground-based EAS experiments without muon measurement facilities.