Cosmic Ray Simulation with PYTHIA

TL;DR

This paper discusses enhancements in PYTHIA for simulating hadronic cascades in cosmic ray air showers, focusing on improved models for nuclear collisions and consistency in results for high-energy particles.

Contribution

It introduces updated models in PYTHIA for better simulation of hadronic cascades, especially at low energies, ensuring consistent results for cosmic ray air showers.

Findings

Models produce consistent results for proton and nucleus-initiated air showers.

Enhanced low-energy collision modeling improves simulation accuracy.

Updated nuclear models align with observed cosmic ray phenomena.

Abstract

We present recent developments in PYTHIA for the modelling of hadronic cascades in a medium. Several improvements have been made in the Angantyr model for collisions with nuclei, especially in the limit of low collision energies, allowing it to be used throughout the hadronic cascades. Also the simplified nuclear model in the PythiaCascade} module has been updated. We find that the two models give consistent results for cosmic ray air showers initiated by both high energy protons and nuclei.