Dependence of Simulated Atmospheric Antiproton Flux on the Microscopic Models of Particle Interactions

Abstract

Influence of the microscopic particle interaction models on the simulations of atmospheric antiproton fluxes at various altitudes is examined by comparing the Monte Carlo simulated results with those obtained from the BESS observations. Some discrepancies between the simulated results and those obtained by the BESS experiments have been noticed, particularly at high altitudes and at the low energy end of the spectrum. More importantly, the predictions of different interaction models also differ from each other. An estimate of the magnitude of uncertainty in the predictions of atmospheric antiproton fluxes in the energy range of about 0.2-100 GeV at balloon altitude due to the uncertainties in the particle interaction characteristics has been made. The present findings may have some implications in the interpretation of precise galactic antiproton flux as observed recently by the PAMELA experiment.