On the Structure of Extensive Air Showers

Abstract

Assuming a simple model of extremely high energy collisions we investigate the relation between the one-dimensional development of extensive air showers (EAS) and the mechanism of multiple mes.on production. The gross structure of EAS based on the model is given graphically or numerical!y, in a form useful, as a first step, for further investigations. In particular, varying the value of in­ elasticity of high energy collisions we discuss its effect on various quantities. As a preliminary con­ clusion it is shown that it seems difficult to explain the experimental result of the constancy of the attenuation length of the electron component over a ·wide range of primary energies, 10l4~10l7eV, without introducing any energy dependence of the inelasticity or a stronger energy dependence of multiplicity with increasing energy, though. it is desirable that further experiments furnish us with more abundant and reliable data. Attention will also be paid to the problem of what quantities must be measured to determine more directly and less ambiguously the angular and energy distribu­ tions of secondary particles produced by high energy collisions. § I. Introduction The purpose of this paper is to analyse the structure of extensive air showers (EAS). with a vtew of investigating the mechanism of multiple meson production in extremely high· energy collisions. The skeleton of EAS is the nucleonic cascade process in the atomosphere developed due to high energy collisions, through which particles of other components, namely electrons, photons; muons, etc., are produced secondarily. There are not very many analyses of EAS which treat this process directly, because the mathematical treatments are very difficult and the process of high energy collisions involves many un. known factors. The works which have been published may be roughly classified into two types : (a) Existing theories of multiple meson production are applied to. analyse EAS and they are examined accordin5 to whether or not they can explain experimental results well. (b) A phenomenological model is assumed and parameters introduced in it are fitted by comparison with experimental data. The works of Amaldi et aVl and Oda2l belong to the former and those of the Soviet group,3 ·4 ·5J Messel et al.6 •7l and Budini