Speaker
Description
Ultra-high energy cosmic rays impinging on the Earth’s atmosphere offer a unique opportunity to probe hadronic interactions at the highest energies through measurements of the extensive air showers they generate. In this work, we introduce a semi-analytic mapping between new macroscopic variables describing the first ultra-high-energy proton-air interaction and the shower-to-shower values of the depth of the shower maximum, $X_{\max}$, and the shower muon number. The distributions of these variables are examined across different kinematic regions of the proton-air interaction and various hadronic interaction models. We also investigate the impact of small perturbations in these distributions on the moments of the $X_{\max}$ and muon number distributions. Finally, we demonstrate how the joint distribution of these first interaction variables maps onto the joint distribution of muon numbers and $X_{\max}$, and how this relationship can be inverted to constrain the shape of multiparticle production variable distributions in proton-air interactions at energies beyond current accelerator capabilities.
