The First Array-Wide Diffuse Flux Search for UHE Neutrinos with the Askaryan Radio Array

Alan Salcedo-Gomez; Marco Stein Muzio; for the ARA Collaboration

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arXiv · 2608.30989

The First Array-Wide Diffuse Flux Search for UHE Neutrinos with the Askaryan Radio Array

Alan Salcedo-Gomez·Marco Stein Muzio·for the ARA Collaboration

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Abstract

The Askaryan Radio Array (ARA) is an ultrahigh energy (UHE) neutrino detector at the South Pole that searches for impulsive broadband radio signals from neutrino-induced particle showers in glacial ice. ARA consists of five autonomous stations with receiving antennas deployed up to 200 m deep and has accumulated the largest livetime of any in-ice radio array. We present the first array-wide diffuse UHE neutrino search using data collected from January 2013 to December 2023, incorporating improved detector characterization and simulation, including data-driven noise and electronics models, revised antenna responses, and updated neutrino interaction and lepton propagation modeling, within a unified framework for event processing, background rejection, and cut optimization across independently operating stations. This search is expected either to identify the first UHE neutrino candidates observed by an in-ice radio detector or to set the most stringent UHE neutrino diffuse flux limits above a few EeV, while informing analysis strategies for under-construction and future radio arrays, such as RNO-G and IceCube-Gen2 Radio.

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Alan Salcedo-Gomez, Marco Stein Muzio, for the ARA Collaboration. 2026-08-31. The First Array-Wide Diffuse Flux Search for UHE Neutrinos with the Askaryan Radio Array. https://arxiv.org/abs/2608.30989

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