Search for Ultra-High Energy Neutrinos with the Pierre Auger Observatory

Search for ultra-high energy neutrinos with the Pierre Auger Observatory

M. Trini for the Pierre Auger Collaboration

Poster

TAU 2018 - The 15th International Workshop on Tau Lepton Physics Amsterdam, Sept 24-28 2018 The Pierre Auger Observatory

• The largest ultra-high energy (1018 eV) cosmic ray detector in the world • Studying extensive particle air showers with: 1660 water Cherenkov detectors over 3000 km² + 27 atmospheric fluorescence telescopes

• From the existence of EeV cosmic rays ⇨ neutrinos at similar energies produced by the interaction of accelerated protons or nuclei: 1. with matter or radiation fields at the astrophysical source 2. with the cosmic microwave background photons when traveling intergalactic distances (cosmogenic neutrinos) Ultra-high energy neutrino production with radiation

with matter

" " Ultra-high energy neutrino in Auger • The array of water Cherenkov stations of the Pierre Auger Observatory is sensitive to neutrino-induced showers above 1017 eV. • The discrimination between cosmic ray and neutrino-induced showers is maximized for nearly horizontal events at early stage of development (the first interaction CC/NC deep in the atmosphere) ⇨ electromagnetic component reaches the ground. Selection procedure

1. elongated pattern on the ground 2. speed of signal close to speed of light

EM signal

3.Signal in PMTs broad in time μ signal

⇨ MC simulations! Ultra-high energy neutrino – LIGO events

• gravitational waves transients ⇨ targeted searched ⇨ no candidates (Auger, IceCube, ANTARES) • first upper limit energy radiated in ultra-high energy neutrinos by compact objects merger Limits to diffuse flux of ultra-high energy νs

• from 1 January 2004 to 31 March 2017 • proton primaries excluded 90% C.L. Limits to pointlike sources of ultra-high energy νs

• Bounds on point sources as a function of declination Conclusions

• The Pierre Auger Observatory, the largest UHE Cosmic-Ray detector in the world, is also sensitive to all flavors of neutrinos of energies around and above 1018 eV.

• Auger covers a large fraction of the sky with declination approx. from - 80 to +60 deg.

• Search for ultra-high energy neutrino emission is complementary to dedicated neutrino experiments IceCube/ANTARES.

• No neutrino candidates found in the ultra-high energy range in data January 2004 - March 2017 …

• Neutrino observatories can provide information on astrophysics (constrains on sources of UHE Cosmic-Rays) and particle physics (neutrino cross-section, Beyond SM models,...).