Comparison of Geant4 hadron generators with data: a critical appraisal

TL;DR

This paper critically evaluates Geant4 hadron generators by comparing their predictions with experimental data, revealing significant discrepancies in secondary particle spectra and angular distributions, which impact detector simulations.

Contribution

It provides a detailed comparison of Geant4 models with experimental data, highlighting areas where the models do not accurately reproduce observed particle spectra and angular distributions.

Findings

Significant disagreements in secondary proton spectra

Discrepancies in pion angular distributions

Implications for detector simulation accuracy

Abstract

Hadron generation models are indispensable for the simulation and calibration of particle physics detectors. The models used by the Geant4 simulation tool kit are compared with inclusive spectra of secondary protons and pions from the interactions with beryllium nuclei of +8.9 GeV/c protons and pions, and of -8.0 GeV/c pions. We report on significant disagreements between data and model predictions especially in the polar-angle distributions of secondary protons and pions.