Neutrino Telescope Array (NTA): Prospect towards Survey of Astronomical $\nu_\tau$ Sources

Abstract

The recent observation of astrophysical PeV neutrino events by IceCube opens a new chapter in neutrino astronomy, calling for improved point-back abilities and increased sensitivity to fill the gap between IceCube and Auger and probe for PeV-EeV neutrino point sources. By separating ν τ → τ conversion from τ-shower generation, the Earth-skimming ν τ method allows for huge target mass and detection volume simultaneously. The Ashra-1 detector, in operation up Mauna Loa on Hawaii Big Island, has demonstrated the feasibility in a 1 st search for ν τ from a GRB. With design based on this experience, a Neutrino Telescope Array (NTA) observatory is being planned: it will have three site stations watching the air mass surrounded by Mauna Loa, Mauna Kea, and Hualalai, plus a central site station watching the lower night sky. Sensitivities equivalent to > 100 km 3 water and pointing accuracy of < 0.2 • can be achieved with Cherenkov-fluorescence stereoscopic observation for PeV-EeV neutrinos that is almost background-free. With the scientific goal of clear discovery and identification of astronomical ν τ sources, a new International Collaboration is being formed to probe for cosmic proton accelerators.

Trinity: The PeV Neutrino Observatory

“…The MAGIC Collaboration has demonstrated a PeV energy threshold and expected sensitivities by pointing their instrument at the Atlantic [11]. The ASHRA and NTA teams built IACTs dedicated to neutrino observations and pointed their telescopes at Mauna Kea [12,13]. The Trinity concept varies from these conceptually and in instrument design.…”