$X_\text{max}$ reconstruction from amplitude information with AERA

TL;DR

This paper discusses methods to reconstruct the atmospheric depth of shower maximum ($X_{max}$) from radio amplitude data collected by AERA, enabling high-duty-cycle cosmic ray mass composition analysis.

Contribution

It introduces new $X_{max}$ reconstruction techniques based on radio amplitude measurements with AERA, improving mass composition studies of cosmic rays.

Findings

Radio amplitude correlates with $X_{max}$

High duty cycle enables large-scale analysis

Methods achieve accurate $X_{max}$ estimation

Abstract

The standard method to estimate the mass of a cosmic ray is the measurement of the atmospheric depth of the shower maximum ($X_\text{max}$). This depth is strongly correlated with the mass of the primary because it depends on the interaction cross section of the primary with the constituents of the atmosphere. Measuring the electric field, emitted by the secondary particles of an extensive air shower (EAS), with the Auger Engineering Radio Array (AERA) in the 30-80 MHz band allows the determination of the depth of shower maximum on the basis of the good understanding of the radio emission mechanisms. The duty cycle of radio detectors is close to 100\%, making possible the statistical determination of the cosmic-ray mass composition through the study of a large number of cosmic rays above 10$^{17}$ eV. In this contribution, $X_\text{max}$ reconstruction methods based on the study of the radio signal with AERA are detailed.