Sensitivity to primary composition and hadronic models from average shape of high energy cosmic ray shower profiles

TL;DR

This paper investigates how the average shape of high energy cosmic ray shower profiles, characterized by the Universal Shower Profile, can reveal information about primary composition and test hadronic interaction models.

Contribution

It introduces a method using shape variables of shower profiles to determine cosmic ray composition and evaluate hadronic models independently of cross-section uncertainties.

Findings

Shape variables are sensitive to primary mass composition.

Compatibility of shape variables tests hadronic model validity.

Method provides a new way to analyze cosmic ray data.

Abstract

The concept of Universal Shower Profile is used to characterize the average behavior of high energy cosmic rays. The shape variables contain important information about composition. They are independent of the primary cross-section by construction, but affected by other hadronic parameters, like multiplicity. The two variables give access to the average nuclear mass of the sample and their compatibility serves as a test of hadronic models.