Multi-messenger physics with the Pierre Auger Observatory and the Southern Wide-field Gamma-ray Observatory

Abstract: he Pierre Auger Observatory, the world's largest experiment in the study of the highest energy astroparticles, is currently undergoing an upgrade to enhance its UHE cosmic ray detection capabilities further. On the other hand, the Southern Wide-field Gamma-ray Observatory, a next-generation experiment aiming to look for PeVatron sources in the centre of our Galaxy, is currently on an R&D phase to concept, design and plan its construction at a high altitude in South America.

Given the energy overlap between these observatories and their current set of conditions, there is a privileged opportunity to explore strategies to boost the capabilities of the Pierre Auger Observatory and the SWGO in detecting astroparticle multi-messenger phenomena. In this presentation, I will discuss the efforts aimed at enhancing the multi-messenger capabilities of both gamma-ray array observatories.

Specifically, I will demonstrate how these observatories can efficiently detect astrophysical neutrinos without incurring additional costs, by leveraging inclined shower events. Additionally, I will illustrate how the energy thresholds of these observatories can be lowered through the implementation of a dedicated trigger strategy. Furthermore, novel gamma/hadron discrimination observables will be introduced, showcasing their ability to surpass muon counting in arrays similar to SWGO, while also exhibiting promising performance in larger, sparser arrays like the Pierre Auger Observatory.