Model-Stable Universality of the Air Shower Electromagnetic Component: an Approach to Solving the Mass Composition Problem

TL;DR

This paper demonstrates that the radial scale factor of electrons in air showers, based on the universality of shower development, can effectively estimate primary cosmic ray mass and improve composition analysis across various models.

Contribution

It introduces a universal relation between the radial scale factor and longitudinal age, enhancing primary mass estimation in cosmic ray studies.

Findings

Radial scale factor is a promising primary mass estimator.

Universality property improves composition results.

Sensitivity to hadronic interaction models is analyzed.

Abstract

On the basis of the scaling approach and CORSIKA simulations data the radial scale factor of lateral distribution of electrons in extensive air showers is confirmed as potentially effective primary mass estimator, and its sensitivity to hadronic interaction model is investigated. It is shown that improved composition results both on average and event-by-event basis can be achieved taking into account the universality property of air shower development expressed by the relation between radial scale factor and longitudinal age parameter. The enhancements of such a theoretically motivated tool for the unbiased cosmic ray composition deduction in a wide primary energy range from (multi-)hybrid air shower measurements of nearest future are discussed.