The multiplicity of secondary production in high-energy interactions

Summary  A fireball model is proposed in which hadronic interactions are described by a sequence of two processes. In the first the nucleon or nucleons absorb the entire available energy, forming an excited body or bodies. The second consists of the decay of this body with emission of the nucleon in its initial direction. For nucleon-nucleon collisions this leads immediately to an asymptoticE 1/4 multiplicity relation. But for hadronic interactions of pions, photons, and muons anE 1/2 multiplicity law is obtained. The calculated average numbers of secondaries are in satisfactory agreement with present data onN-N and π-N interactions. Applied to a description of the longitudinal development of an air shower the model predicts a location of the cascade maximum only slightly deeper than that found if anE 1/2 multiplicity relation is assumed for bothN-N and π-N collisions, and distinctly higher than that derived for anE 1/4 law in both types of interaction. Thus it makes unnecessary the assumption, suggested by several authors in their analysis of air showers, that the characteristics of hadronic interactions undergo a drastic change at high primary energies.