Composition Classification of Ultra-High Energy Cosmic Rays

Abstract

The study of cosmic rays remains as one of the most challenging research fields in Physics. From the many questions still open in this area, knowledge of the type of primary for each event remains as one of the most important issues. All of the cosmic rays observatories have been trying to solve this question for at least six decades, but have not yet succeeded. The main obstacle is the impossibility of directly detecting high energy primary events, being necessary to use Monte Carlo models and simulations to characterize generated particles cascades. This work presents the results attained using a simulated dataset that was provided by the Monte Carlo code CORSIKA, which is a simulator of high energy particles interactions with the atmosphere, resulting in a cascade of secondary particles extending for a few kilometers (in diameter) at ground level. Using this simulated data, a set of machine learning classifiers have been designed and trained, and their computational cost and effectiveness compared, when classifying the type of primary under ideal measuring conditions. Additionally, a feature selection algorithm has allowed for identifying the relevance of the considered features. The results confirm the importance of the electromagnetic-muonic component separation from signal data measured for the problem. The obtained results are quite encouraging and open new work lines for future more restrictive simulations.

Feature Selection Techniques for CR Isotope Identification with the AMS-02 Experiment in Space

“…ML-driven feature selection techniques are emerging as suitable tools to optimise the performance of ML algorithms for classification tasks in particle [16] and astroparticle physics [17][18][19]. Furthermore, feature selection has already been used in cosmic ray identification for ground-based experiments in Herrera et al [20] to rank the relevance of features involved in primary particle reconstruction from air shower simulations. The importance of feature selection lies in its ability to simplify the data analysis process.…”