Probing Hadronic Interactions with Cosmic Rays

TL;DR

This paper discusses how cosmic ray-induced air showers serve as a natural laboratory to study hadronic interactions in extreme conditions, complementing collider experiments and testing QCD models.

Contribution

It highlights the potential of EAS measurements to probe non-perturbative QCD processes that are inaccessible to current collider experiments.

Findings

EAS development is driven by low momentum transfer hadron-ion collisions.

Cosmic rays provide a unique probe of multi-particle production in hadronic interactions.

Accurate EAS measurements can test and improve QCD models in extreme regimes.

Abstract

High-energy cosmic rays interact in the Earth's atmosphere and produce extensive air showers (EASs) which can be measured with large detector arrays at the ground. The interpretation of these measurements relies on models of the EAS development which represents a challenge as well as an opportunity to test quantum chromodynamics (QCD) under extreme conditions. The EAS development is driven by hadron-ion collisions under low momentum transfer in the non-perturbative regime of QCD. Under these conditions, hadron production cannot be described using first principles and these interactions cannot be probed with existing collider experiments. Thus, accurate measurements of the EAS development provide a unique probe of multi-particle production in hadronic interactions.