Air Fluorescence Relevant for Cosmic-Ray Detection - Summary of the 5th Fluorescence Workshop, El Escorial 2007

TL;DR

This paper summarizes the discussions and latest research on air fluorescence light yield relevant for cosmic-ray air shower detection, focusing on experimental and theoretical advances and atmospheric dependencies.

Contribution

It compiles recent progress from the 5th Fluorescence Workshop on understanding fluorescence light yield and its atmospheric dependencies for cosmic-ray measurements.

Findings

Updated measurements of fluorescence light yield in air.

Analysis of atmospheric effects on fluorescence emission.

Implications for cosmic-ray energy scale calibration.

Abstract

High-energy cosmic rays with energies exceeding $10^{17}$ eV are frequently observed by measurements of the fluorescence light induced by air showers. A major contribution to the systematic uncertainties of the absolute energy scale of such experiments is the insufficient knowledge of the fluorescence light yield of electrons in air. The aim of the 5th Fluorescence Workshop was to bring together experimental and theoretical expertise to discuss the latest progress on the investigations of the fluorescence light yield. The results of the workshop will be reviewed as well as the present status of knowledge in this field. Emphasis is given to the fluorescence light yield important for air shower observations and its dependence on atmospheric parameters, like pressure, temperature, and humidity. The effects of the latest results on the light observed from air showers will be discussed.