Description
The Pierre Auger Observatory is able to detect neutrinos with energies above $10^{17}\,$eV using the Surface Detector (SD) array. Neutrinos of all flavors interacting deep in the atmosphere with large zenith angles, $\theta > 60^\circ$, as well as Earth-Skimming $\tau$-neutrinos with nearly tangential trajectories can be efficiently identified. No neutrino candidates have been found in $\sim$ 14.7 years of available data collected up to 31.12.2018. The stringent upper bounds lead to strong constraints on various theoretical models regarding ultra-high energy neutrinos and cosmic ray productions at EeV energies. A dedicated search towards neutrinos emitted from point-like sources lead to corresponding upper bounds with respect to the source declination.
Neutrino transient sources have also been investigated and searches towards high-energy neutrinos in coincidence with the neutron star merger GW170817 as well as neutrinos from the blazar TXS056+056 direction have been performed. The results within both studies have been analyzed in multiple time windows. As no neutrino excess has been found, upper bounds on the neutrino fluence from GW170817 have been set and the consequences of the non observation of neutrinos from TXS056+056 have been studied. Additionally the Pierre Auger Observatory has also performed follow-up searches of ultra-high energy neutrinos following the binary black hole (BBH) mergers. Corresponding upper limits on the neutrinos luminosity with respect to the time after the merger are given for the constantly updated BBH mergers.
More exotic events, similar to the ANITA anomalous events, in terms of steeply up-going air showers, can also be observed using the Fluorescence Detector (FD) of the Pierre Auger Observatory. A dedicated search has been performed and corresponding upper flux limits have been set. The results are presented in terms of $\tau$-induced air showers and could be further extended in terms of neutrinos and Beyond Standard Model (BSM) particles.
| Collaboration | Pierre Auger Collaboration |
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