Study on the combined estimate of the cosmic-ray composition and particle cross-sections at ultrahigh energies

Discussion timeslot (ZOOM-Meeting): 14. July 2021 - 18:00
ZOOM-Meeting URL: https://desy.zoom.us/j/92210078166
ZOOM-Meeting ID: 92210078166
ZOOM-Meeting Passcode: ICRC2021
Corresponding Session: https://icrc2021-venue.desy.de/channel/03-Muon-Puzzle-and-EAS-modeling-CRI/110
Live-Stream URL: https://icrc2021-venue.desy.de/livestream/Discussion-03/4

Abstract:
'The mass composition is one of the key observables to understand the nature and origin of ultrahigh-energy cosmic rays (UHECRs). The study of hadronic interactions at energies well beyond human-made accelerators is a fundamental probe of elementary particle physics. In previous analyses, the properties of the hadronic interactions were estimated under the assumption of a certain mass composition, typically proton-dominated, and the cross-sections were calculated by fitting the tail of the $X_mathrm{max}$ distribution. In such an analysis, the impact of a possible He-contamination on the cross-section measurement is quoted as a systematic uncertainty. Vice versa, the cosmic-ray mass composition is typically determined using air shower simulations by assuming the validity of the considered hadronic interaction models.rnrnIn this contribution, we present a fully self-consistent approach of varying the proton-proton cross-sections, with the nucleus-nucleus cross-sections being predicted via the Glauber theory, and making a full $X_mathrm{max}$ distribution fit to get an independent and simultaneous estimation of the interaction cross-sections and cosmic-ray primary composition. We will discuss the degeneracy between mass composition and hadronic interactions and compare the sensitivity of the proposed method to the one of previous approaches.'

Authors: Olena Tkachenko
Co-Authors: Ralph Engel | Ralf Ulrich | Michael Unger
Indico-ID: 1059
Proceeding URL: https://pos.sissa.it/395/438