Optimizing underwater neutrino telescopes for all-flavor point source sensitivity
Phys. Rev. D 113, 043030 – Published 17 February, 2026
DOI: https://doi.org/10.1103/73dh-tmgr
Abstract
High-energy neutrino astronomy has advanced rapidly in recent years, with IceCube, KM3NeT, and Baikal-GVD establishing a diffuse astrophysical flux and pointing to promising source candidates. These achievements mark the transition from first detections to detailed source studies, motivating next-generation detectors with larger volumes, improved angular resolution, and full neutrino-flavor sensitivity. We present a performance study of large underwater neutrino telescopes, taking the proposed TRIDENT array in the South China Sea as a case study, with a focus on comparing the performance of various detector configurations against the TRIDENT baseline design. Both tracklike events primarily from muon neutrinos, which provide precise directional information, and cascade events from all flavors, which offer superior energy resolution, diffuse-source sensitivity, and all-sky flavor coverage, are included to achieve a balanced performance across source types. The time to discover potential astrophysical sources with both tracklike and cascadelike events is used as the figure of merit to compare a variety of detector design choices. Our results show that, for a fixed number of optical modules, simply enlarging the instrumented volume does not inherently lead to improved performance, while taller strings can provide modest gains across all detector channels, within engineering constraints. Distributing dense clusters of strings over a large volume is found to generally worsen discovery potential compared to the baseline layout. Finally, the optical properties of the seawater emerge as the key factor dictating the optimization of detector layout, highlighting the need for in situ measurements and early deployment of optical modules to guide the final array configuration.