Determination of the energy scale of cosmic ray measurements using the Auger Engineering Radio Array

The accurate determination of the absolute energy scale in cosmic ray
measurements is both a challenging and fundamentally important task. In this contribution, we present how measurements of radio pulses from extensive air showers with the Auger Engineering Radio Array, combined with per-event simulations of radio emission using the CoREAS extension of CORSIKA, allow us to determine the energy scale of cosmic rays between 3 \times 10^{17} eV and several 10^{18} eV.
Our analysis accounts for many factors, each of them controlled on the 5%
level or better. The absolute calibration of the antennas and the entire
analog signal chain builds on a Galactic calibration in combination with a detailed understanding of the antenna gain patterns. Additional key elements include compensation for temperature-dependent signal amplification, continuous detector health monitoring, an active veto for thunderstorm conditions, an unbiased event reconstruction, and per-event atmospheric modeling in the simulations. The analysis benefits from a high-statistics dataset of over 800 measured cosmic-ray showers.
We describe our analysis method, perform multiple cross-checks, and evaluate systematic uncertainties. ... mehrFinally, we determine the energy scale of cosmic rays using the Auger Engineering Radio Array and compare it to the energy scale of the Pierre Auger Observatory, as established by the Fluorescence Detector.