Approaches to composition independent energy reconstruction of cosmic rays based on the LHAASO-KM2A detector

Abstract

The kilometer-square array (KM2A) of the Large High Altitude Air Shower Observatory (LHAASO, located at 4410 m above sea level with an atmospheric depth of $600\text{ }\text{ }\mathrm{g}/{\mathrm{cm}}^{2}$) can simultaneously measure air shower sizes of both electromagnetic particles and muon contents with high precision for cosmic rays with energies in the knee region. An advantage of the LHAASO experiment is that it can be performed at the maximum depth of air showers of cosmic rays in the knee region. In this study, different methods to reconstruct the cosmic ray energy are investigated, including those based on traditional and combined parameters. The traditional methods based on ${N}_{\mathrm{size}}$ or ${\ensuremath{\rho}}_{50}$ to reconstruct the primary energy are dependent on the cosmic ray components. Based on Heitler's electromagnetic and Matthews' hadronic shower models, two combined parameters of ${N}_{e*\ensuremath{\mu}}$ and ${N}_{e\ensuremath{\mu}}$ are proposed. The examination of cosmic ray energy reconstruction methods based on the LHAASO-KM2A detector by combining the parameters of muons and electromagnetic particles, and the simulation results, confirmed the reduction in component dependence and bias of individual components. The dependence of energy reconstruction on hadronic interaction models is also discussed.