Cosmic ray event generator Sibyll 2.1

TL;DR

Sibyll 2.1 is an improved cosmic ray event generator that enhances simulation accuracy by incorporating multiple soft interactions, new parton densities, and better diffraction modeling, aligning more closely with experimental data.

Contribution

The paper introduces Sibyll 2.1 with structural enhancements over version 1.7, improving simulation fidelity for cosmic ray interactions.

Findings

Better agreement with fixed target and collider data.

Improved modeling of inelastic cross sections and particle multiplicities.

Identified areas for future development.

Abstract

The cosmic ray interaction event generator Sibyll is widely used in extensive air shower simulations. We describe in detail the properties of Sibyll 2.1 and the differences with the original version 1.7. The major structural improvements are the possibility to have multiple soft interactions, introduction of new parton density functions, and an improved treatment of diffraction. Sibyll 2.1 gives better agreement with fixed target and collider data, especially for the inelastic cross sections and multiplicities of secondary particles. Shortcomings and suggestions for future improvements are also discussed.