Dual parton model at cosmic ray energies

The dual parton model for hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions is studied in the fragmentation region up to the cosmic ray energy region. Because of the excellent Feynman scaling behavior of the model outside the regions around ${\mathit{x}}_{\mathit{F}}$=1 and ${\mathit{x}}_{\mathit{F}}$=0, it is found that accelerator data in the fragmentation region are indeed relevant for the cosmic ray energy region. However, not enough data are available in the fragmentation region of hadron collisions with light target nuclei. Therefore many features of hadron production in collisions involving nuclei can only be extracted from the study of models.