Probing the origin of ultra-high-energy cosmic rays with neutrinos in the EeV energy range using the Pierre Auger Observatory
Abstract
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 similar to 14.7 years of data taken up to 31 August 2018. This leads to restrictive upper bounds on their flux.
The 90% C.L. single-flavor limit to the diffuse flux of ultra-high-energy neutrinos with an E-nu(-2) spectrum in the energy range 1.0 x 10(17) eV-2.5 x 10(19) eV is E(2)dN(nu)/dE(nu) < 4.4 x 10(-9) GeV cm(-2) s(-1) sr(-1), placing strong constraints on several models of neutrino production at EeV energies and on the properties of the sources of ultra-high-energy cosmic rays.