Constraining the energy spectrum of neutral pions in ultra-high-energy proton-air interactions

TL;DR

This paper demonstrates how analyzing muon content fluctuations in air showers can constrain the high-energy neutral pion spectrum in initial cosmic ray interactions, improving understanding of particle physics at ultra-high energies.

Contribution

It introduces a method to constrain the neutral pion energy spectrum in proton-air interactions using muon fluctuation data from cosmic ray air showers.

Findings

The high-energy tail of the neutral pion spectrum can be constrained within current experimental uncertainties.

Muon fluctuation analysis provides insights into the first interaction physics of cosmic rays.

The approach enhances understanding of particle production at ultra-high energies.

Abstract

Fluctuations in the muon content of extensive air showers are anticorrelated to the fluctuations of the energy taken by the neutral pions which emerge from the first interaction of the cosmic ray in the atmosphere. We show that the high-energy tail of the neutral pion spectrum produced in the first proton-air interaction can be constrained, within the uncertainties of present cosmic ray experiments, through the analysis of the shower-to-shower distribution of the muon content of the air showers, $P(N_{\mu})$.