Validation of Geant4 Physics Using 1996 CMS HCAL Test Beam Data

Various hadronic physics models of Geant4 are validated for the first time using the 1996 test beam data of the CMS hadron calorimeter. Detailed comparison have been carried out on energy response, energy resolution and longitudinal shower profiles between the test beam data with electron and pion beams at different energies and simulation of the associated setup with different models in Geant4 and Geant3. Gross features in the data, like non-linearity in energy response, energy resolution, etc. are well reproduced by the Monte Carlo models. There are some disagreements in some of the details like longitudinal shower profiles or the e/h ratio.