Probing the origin of ultra-high-energy cosmic rays with neutrinos in the EeV energy range using the Pierre Auger Observatory

Understand

Neutrinos with energies above $10^{17}$ eV are detectable with the Surface Detector Array of the Pierre Auger Observatory.

• The identification is efficiently performed for neutrinos of all flavors interacting in the atmosphere at large zenith angles, as well as for Earth-skimming $\tau$ neutrinos with nearly tangential trajectories relative to the earth.
• No neutrino candidates were found in $\sim\,14.7$ years of data taken up to 31 August 2018.
• This leads to restrictive upper bounds on their flux.