Systematic uncertainty of first-principle calculations of the radiation energy emitted by extensive air showers

¹ Bergische Universität Wuppertal, Gauβstraβe 20, 42119 Wuppertal Germany
² RWTH Aachen University, III. Physikalisches Institut A, Aachen, Germany
³ Department of Physics and Astronomy, University of California, Irvine, USA
⁴ Karlsruher Institut für Technologie, Institut für Kernphysik, Postfach 3640, 76021 Karlsruhe, Germany
⁵ Vrije Universiteit Brussel, Astrophysical Institute, Pleinlaan 2, 1050 Brussels, Belgium

^★ e-mail: gottowik@uni-wuppertal.de

Published online: 24 September 2019

Abstract

The energy of extensive air showers can be determined from the energy radiated in the form of radio signals. The so-called radiation energy can be predicted with modern simulation codes using first-principle calculations without the need of free parameters. Here, we verify the consistency of radiation energy calculations by comparing a large set of Monte Carlo simulations made with the two codes CoREAS and ZHAireS. For the frequency band of 30 — 80 MHz, typically used by many current radio detectors, we observe a difference in the radiation energy prediction of 5.2%. This corresponds to a radio emission modelling uncertainty of 2.6% for thedetermination of the absolute cosmic-ray energy scale. Hence, radio detection offers the opportunity for a precise, accurate and independent measurement of the absolute energy of cosmic rays.