Evidence for change in the characteristics of strong interactions at ultra-high energies

Abstract

An attempt has been made to understand the experimental results on the size dependence of several properties of high energy hadrons reported in a previous paper (see ibid., vol.6, no.7, 1050 of 1973) in terms of the characteristics of high energy collisions and primary composition using detailed Monte Carlo simulations. It is shown that the behaviour of the high energy hadron component, especially the size dependence, cannot be accounted for in terms of a change of primary composition alone in the energy range 10¹⁴-10¹⁶ eV which has been suggested by some of the earlier investigations to explain certain properties of air showers. The present analysis strongly suggests the need for invoking rather drastic changes in the characteristics of strong interactions at ultra-high energies.