Inclusive fluxes of secondary air-shower particles

Abstract

The particle showers produced in the atmosphere due to the interactions of primary cosmic particles require a thorough understanding in the backdrop of searches for rare interactions. In this work, we made a comprehensive study of air shower simulations using various combinations of hadronic models and particle transport code of the CORSIKA package. The primary proton and helium distributions are taken as power law which are scaled to match the measured flux in balloon experiments at the top of atmosphere. The shower simulation includes production, transport, and decays of secondaries up to the ground level. In this study, we focus on the bulk of the spectra and particles which is computationally intensive and hence parallel processing of events is done on computer cluster. We provide a way to normalize the simulation results to be compared with the ground-based measurements namely, single and multiple muon yields and their charge ratios as a function of zenith angle and momentum. This provides a basis for comparisons among the six model combinations used in this study and the differences are outlined. Most of the hadronic models in CORSIKA produce the bulk ground based measurements fairly well. We use one of the best model combinations to quantitatively predict the absolute and relative yields of various particles at ground level as well as their correlations with primaries and with each other. The leptonic ratios are obtained as a function of energy and zenith angle which are important inputs for the neutrino oscillation physics.