Mass hierarchy and CP-phase sensitivity of ORCA using Fermilab Neutrino Beam

Abstract: We explore neutrino mass hierarchy determination and CP-phase measurement using multi-megaton water Cherenkov detector KM3NeT-Oscillation Research with Cosmics in the Abyss (ORCA) in the Mediterranean sea receiving neutrino beam from the Fermilab Long Baseline Neutrino Facility (LBNF) over 6900 km baseline. We find that with the proposed beam luminosity of $1.2\times 10^{21}$ proton-on-target per year, it will be possible to determine mass hierarchy at $\gtrsim 4\,\sigma$ confidence level within 1 year in the neutrino mode alone. A combined 1 year in neutrino and 1 year in antineutrino mode can determine hierarchy at $\gtrsim 6\,\sigma$ confidence level. We also find that a non-zero CP-phase can be detected with up to $\sim 1.8\,\sigma$ significance after 10 years of data taking. We explore degeneracy of neutrino oscillation parameters and uncertainties in detection efficiencies affecting the results.