Experimental evidence for the sensitivity of the air-shower radio signal to the longitudinal shower development

TL;DR

This study demonstrates experimentally that radio signals from cosmic-ray air showers are sensitive to their longitudinal development, which is crucial for future ultra-high-energy cosmic ray detection and analysis.

Contribution

It provides the first experimental evidence linking radio lateral distribution slopes to the shower's longitudinal development.

Findings

Radio lateral distribution slopes correlate with muon pseudorapidity

Radio measurements are sensitive to shower development

Supports use of radio arrays in cosmic-ray physics

Abstract

We observe a correlation between the slope of radio lateral distributions, and the mean muon pseudorapidity of 59 individual cosmic-ray-air-shower events. The radio lateral distributions are measured with LOPES, a digital radio interferometer co-located with the multi-detector-air-shower array KASCADE-Grande, which includes a muon-tracking detector. The result proves experimentally that radio measurements are sensitive to the longitudinal development of cosmic-ray air-showers. This is one of the main prerequisites for using radio arrays for ultra-high-energy particle physics and astrophysics.