Searches for ultra-high energy photons and neutrinos with the Pierre Auger Observatory

TL;DR

The paper reviews the Pierre Auger Observatory's recent searches for ultra-high energy photons and neutrinos, providing limits that constrain models of dark matter and cosmic-ray sources, thereby advancing multi-messenger astrophysics.

Contribution

It presents the latest results from UHE photon and neutrino searches, setting stringent flux limits and constraining theoretical models of dark matter and cosmic-ray origins.

Findings

Stringent limits on UHE photon fluxes above 10^17 eV.

Stringent limits on UHE neutrino fluxes above 10^17 eV.

Constraints on dark matter decay and cosmic-ray source models.

Abstract

The Pierre Auger Observatory is the largest astroparticle experiment in operation. Complementary to the measurements of the charged ultra-high energy (UHE) cosmic rays, it provides a very good sensitivity to the detection of UHE photons and neutrinos. Since the photon and neutrino fluxes are correlated to the acceleration mechanisms of charged particles, searches for these neutral particles enhance the multi-messenger understanding of UHE cosmic-ray sources and of transient astrophysical phenomena. In addition, searches for diffuse fluxes may bring information about exotic scenarios such as the decay of hypothetical super-heavy dark matter in the Galactic halo. In this contribution, we present an overview of the current UHE photon and neutrino searches at the Observatory and discuss the most recent results. We report on stringent limits to the UHE photon and neutrino diffuse and point-like fluxes above 1017 eV, which lead to strong constraints on theoretical models describing the nature of dark matter candidates and the sources of the most energetic particles in the Universe.