GEANT4 simulation of hadronic interactions at 8–10 GeV/c: response to the HARP-CDP group

The results of the HARP-CDP group on the comparison of Geant4 Monte Carlo predictions versus experimental data are discussed. It is shown that the problems observed by the group are caused by an incorrect implementation of old features at the programming level, and by a lack of the nucleon Fermi motion in the simulation of quasi-elastic scattering. These drawbacks are not due to the physical models used. They do not manifest themselves in the most important applications of the Geant4 toolkit.