Time asymmetries in extensive air showers: a novel method to identify UHECR species

TL;DR

This paper introduces a new method utilizing azimuthal asymmetries in air shower signals to identify ultra-high-energy cosmic ray species, showing potential for improved mass composition determination.

Contribution

The paper presents a novel approach based on time asymmetries in ground signals to determine cosmic ray composition, supported by Monte Carlo sensitivity analysis.

Findings

Asymmetry dependence on atmospheric depth peaks at a position linked to primary species.

The method shows promising sensitivity in Monte Carlo simulations.

Potential for better mass composition analysis in cosmic ray studies.

Abstract

Azimuthal asymmetries in signals of non vertical showers have been observed in ground arrays of water Cherenkov detectors, like Haverah Park and the Pierre Auger Observatory. The asymmetry in time distributions of arriving particles offers a new possibility for the determination of the mass composition. The dependence of this asymmetry on atmospheric depth shows a clear maximum at a position that is correlated with the primary species. In this work a novel method to determine mass composition based on these features of the ground signals is presented and a Monte Carlo study of its sensitivity is carried out.