Measuring Oscillations with a Million Atmospheric Neutrinos

• Published in: Physical Review X
• Main Authors: C. A. Argüelles, P. Fernández, I. Martínez-Soler, M. Jin (靳淼辰)
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Physical Society 2023
• Subjects: Physics; QC1-999; Orca
• Online Access: https://doi.org/10.1103/PhysRevX.13.041055; https://doaj.org/article/2e496709f07b4c96b7041612e6cc82c4

After two decades of measurements, neutrino physics is now advancing into the precision era. With the long-baseline experiments designed to tackle current open questions, a new query arises: Can atmospheric neutrino experiments also play a role? To that end, we analyze the expected sensitivity of current and near-future water(ice)-Cherenkov atmospheric neutrino experiments in the context of standard three-flavor neutrino oscillations. In this first in-depth combined atmospheric neutrino analysis, we analyze the current shared systematic uncertainties arising from the common flux and neutrino-water interactions. We then implement the systematic uncertainties of each experiment in detail and develop the atmospheric neutrino simulations for Super-Kamiokande, with and without neutron-tagging capabilities, IceCube Upgrade, ORCA, and Hyper-Kamiokande detectors. We carefully review the synergies and features of these experiments to examine the potential of a joint analysis of these atmospheric neutrino data in resolving the θ_{23} octant at 99% confidence level (CL), and determining the neutrino mass ordering above 5σ by 2030. Additionally, we assess the capability to constrain θ_{13} and the CP-violating phase (δ_{CP}) in the leptonic sector independently from reactor and accelerator neutrino data. A combination of the atmospheric neutrino measurements will enhance the sensitivity to a greater extent than the simple sum of individual experiment results reaching more than 3σ for some values of δ_{CP}. These results will provide vital information for next-generation accelerator neutrino oscillation experiments such as DUNE and Hyper-Kamiokande.