From collider to cosmic rays: Pythia 8/Angantyr for air shower simulations in CORSIKA 8

TL;DR

This paper discusses integrating Pythia 8/Angantyr into CORSIKA 8 to enhance high-energy cosmic ray air shower simulations, enabling detailed modeling of hadronic interactions and heavy-ion collisions.

Contribution

The paper presents the implementation and validation of Pythia 8/Angantyr within CORSIKA 8, expanding the simulation capabilities for high-energy cosmic ray interactions.

Findings

Pythia 8/Angantyr reproduces key collision observables effectively.

Enhanced modeling of air shower properties like longitudinal development and muon content.

Comparison shows competitive performance against existing models.

Abstract

The simulation of extensive air showers is pivotal for advancing our understanding of high-energy cosmic ray interactions in Earth's atmosphere. The CORSIKA 8 framework is being developed as a modern, flexible, and efficient tool for simulating these interactions with a variety of high-energy hadronic models. We present the ongoing implementation and validation of Pythia 8/Angantyr within CORSIKA 8. Pythia 8, successfully used in collider physics, provides a detailed and well-tested treatment of hadronic interactions, while the Angantyr model extends its capabilities to describe heavy-ion collisions in a consistent manner. With the inclusion of Pythia 8, the CORSIKA 8 suite now enables further tuning possibilities, improving the exploration of hadronic interactions in air showers. In this contribution, we compare the capability of Pythia 8/Angantyr to reproduce fundamental observables of high-energy particle collisions $-$ inelastic cross-sections and multiplicities $-$ to that of several established high-energy interaction models in air shower simulations. We further compare the predictions for key air shower properties, including longitudinal shower development and muon content, for iron-induced shower.