# Study on the Combined Estimate of the Cosmic-Ray Composition and Particle Cross Sections at Ultrahigh Energies

Tkachenko, Olena 1; Engel, Ralph 1; Ulrich, Ralf 1; Unger, Michael 1
1 Institut für Astroteilchenphysik (IAP), Karlsruher Institut für Technologie (KIT)

## Abstract:

The mass composition is one of the key observables to understand the nature and origin of ultra-high energy cosmic rays.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 $X_{max}$ 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.

In 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 $X_{max}$ distribution fit to get an independent and simultaneous estimation of the interaction cross sections and cosmic-ray primary composition. ... mehr

 Zugehörige Institution(en) am KIT Institut für Astroteilchenphysik (IAP) Publikationstyp Proceedingsbeitrag Publikationsdatum 18.03.2022 Sprache Englisch Identifikator ISSN: 1824-8039 KITopen-ID: 1000138546 HGF-Programm 51.13.03 (POF IV, LK 01) Kosmische Strahlung Auger Erschienen in 37th International Cosmic Ray Conference (ICRC 2021): July 12th – 23rd, 2021, Online – Berlin, Germany Veranstaltung 37th International Cosmic Ray Conference (ICRC 2021), Online, 12.07.2021 – 23.07.2021 Verlag Scuola Internazionale Superiore di Studi Avanzati (SISSA) Seiten Art.-Nr.: 438 Serie Proceedings of Science ; 395 Vorab online veröffentlicht am 31.07.2021 Nachgewiesen in Dimensions Relationen in KITopen Verweist aufStudy on the combined estimate of the cosmic-ray composition and particle cross-sections at ultrahigh energies. Tkachenko, Olena; Engel, Ralph; Ulrich, Ralf; Unger, Michael (2021) Vortrag (1000132757)
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