The absorption length of EAS at sea level

Abstract

A simulation of integral size spectra with various assumptions about the primary energy spectrum has been performed at different depths and in several zenith angle bins (0 degrees -40 degrees ). The absorption length Lambda has been derived directly from the data with accurate consideration of the experimental procedures, the angular and barometric methods. A systematic consequence of the steepening of the primary spectrum ('knee effect') is seen to emerge in the behaviour of Lambda as a function of size between 10⁴ and 10⁸ particles. A consecutive interpretation of the present data in terms of dynamical ultra-high-energy interactions reveals a strong disagreement with the Feynman scaling hypothesis.