KM3NeT-ORCA: Oscillation Research with Cosmics in the Abyss

TL;DR

KM3NeT-ORCA is a neutrino detector under construction in the Mediterranean Sea designed to study neutrino oscillations, determine the neutrino mass hierarchy, and explore new physics beyond the Standard Model.

Contribution

This paper presents the design, capabilities, and scientific goals of the KM3NeT-ORCA detector for neutrino oscillation research.

Findings

Sensitivity to the neutrino mass hierarchy at 3σ after 3-4 years

Precision measurement of atmospheric mixing parameters comparable to existing experiments

Ability to probe new physics such as non-standard interactions and sterile neutrinos

Abstract

KM3NeT, currently under construction in the abysses of the Mediterranean Sea, is a distributed research infrastructure that will host a km3-scale neutrino telescope (ARCA) for high-energy neutrino astronomy, and a megaton scale detector (ORCA) for neutrino oscillation studies of atmospheric neutrinos. ORCA is optimised for a measurement of the mass hierarchy, providing a sensitivity of 3{\sigma} after 3-4 years. It will also measure the atmospheric mixing parameters $\Delta m_{32}^2$ and $\theta_{23}$ with a precision comparable to the NOvA and T2K experiments using both the muon neutrino disappearance and tau neutrino appearance channels. It will provide a measurement of the tau neutrino appearance rate with better than 10% precision, a crucial ingredient for tests of unitarity. It will probe the octant of the mixing angle $\theta_{23}$ via matter resonance effects on neutrinos and antineutrinos crossing the core and mantle, which are largely independent on the CP phase. The observation of neutrino oscillations over a wide range of baselines and energies will provide broad sensitivity to new physics such as non-standard neutrino interactions (NSI) and sterile neutrinos.