A Comprehensive Diffuse Neutrino Search Using the Full Askaryan Radio Array

Abstract: The Askaryan Radio Array (ARA) is a neutrino experiment at the South Pole, designed to detect radio-frequency emissions produced by interactions of ultra-high energy (UHE) neutrinos with the Antarctic ice. The array consists of five autonomous stations, each equipped with deep in-ice antennas sensitive to both vertically and horizontally polarized radio signals. With nearly 30 station-years of livetime accumulated, ARA is now conducting its first comprehensive array-wide search for diffuse UHE neutrinos. This analysis is expected to deliver the most stringent constraints from any in-ice radio-based detector up to 1~ZeV and is capable of probing flux levels suggested by KM3NeT around 220~PeV. The results from this analysis marks a critical step toward establishing scalable techniques for next-generation detectors.