Test of hadronic interaction models in the forward region with KASCADE event rates

An analysis of muon and hadron rates observed in the central detector of the KASCADE experiment has been carried out. The data are compared with CORSIKA simulations employing the high-energy hadronic interaction models QGSJET, DPMJET, HDPM, SIBYLL and VENUS. In addition, first results with the new hadronic interaction model neXus 2 are discussed. Differences of the model predictions, both among each other and when confronted with measurements, are observed. The hadron rates mainly depend on the inelastic cross section and on the contribution of diffraction dissociation. The discrepancy between simulations and measurements at low primary energies around 5 TeV can be reduced by increasing the non-diffractive part of the inelastic cross section of nucleon-air interactions. Ali examination of hadron multiplicities points towards harder spectra of secondary pions and kaons being needed in the calculations.