Volume 501 - 39th International Cosmic Ray Conference (ICRC2025) - Cosmic-Ray Indirect
Simulation study of lateral distribution properties of ultra-high energy cosmic ray air showers for the Telescope Array
K. Shinozaki*, M. Przybylak, K. Fujisue, Y. Tsunesada and O.b.o. the Telescope Array Collaboration
*: corresponding author
Full text: pdf
Pre-published on: September 24, 2025
Published on: December 30, 2025
Abstract
Ultra-high energy cosmic rays (UHECRs) are extremely rare and of unknown origin. They are studied indirectly via air showers, but the reconstructed energy scale carries intrinsic uncertainties whose causes are not fully understood. We investigate the lateral distribution of particle densities in UHECR-induced showers simulated for the Telescope Array (TA) surface detectors using CORSIKA with QGSJET-II04, EPOS-LHC, and Sibyll 2.3e. Analyzing detector-level simulation outputs without reconstruction eliminates biases from the array layout and algorithms. The results show systematically steeper lateral distributions than the empirical function used in TA analysis. While 𝑆(800) remains a robust energy estimator, differences from the currently used look-up table
are attributed to idealized versus realistic array assumptions. Hybrid events help calibrate this offset. Dependence on primary particle and interaction model is marginal. These findings support future efforts to derive average lateral distributions from data to constrain related uncertainties.
DOI: https://doi.org/10.22323/1.501.0396
How to cite

Metadata are provided both in article format (very similar to INSPIRE) as this helps creating very compact bibliographies which can be beneficial to authors and readers, and in proceeding format which is more detailed and complete.

Open Access
Creative Commons LicenseCopyright owned by the author(s) under the term of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.