Systematic uncertainty in the analysis of the TA fluorescence detector from fluorescence yield models

Abstract

Currently, ultra-high energy cosmic rays (UHECRs) are being measured by the Telescope Array (TA) and Pierre Auger (Auger) experiments. There are differences in the energy spectra measured by TA and Auger. One reason for this difference is systematic uncertainty in the energy determination. The fluorescence yield model, which consists of fluorescence emission efficiencies and spectra, is one of the most significant components of this systematic uncertainty. Fluorescence emission efficiencies and spectra have been measured by various experiments, and different measurements are currently used to determine the energy of the TA and Auger experiments. In this study, we estimate the influence of the fluorescence yield model on the systematic uncertainty in the energy determination of the TA fluorescence detector.