Capability of the HAWC gamma-ray observatory for the indirect detection of ultra-high energy neutrinos

TL;DR

This paper evaluates the potential of the HAWC observatory, using the Earth-skimming technique and Pico de Orizaba as a target, to detect ultra-high energy neutrinos from cosmic sources.

Contribution

It introduces a novel method to detect ultra-high energy neutrinos with HAWC by leveraging the Earth-skimming technique and a high mountain as a neutrino interaction target.

Findings

Detection rate estimates suggest feasibility of measuring ultra-high energy neutrino flux.

The approach utilizes the Pico de Orizaba volcano as a large mass target for neutrino interactions.

Results indicate potential for cosmic neutrino detection during HAWC's operational lifetime.

Abstract

The detection of ultra-high energy neutrinos, with energies in the PeV range or above, is a topic of great interest in modern astroparticle physics. The importance comes from the fact that these neutrinos point back to the most energetic particle accelerators in the Universe, and provide information about their underlying acceleration mechanisms. Atmospheric neutrinos are a background for these challenging measurements, but their rate is expected to be negligible above $\approx$ 1 PeV. In this work we describe the feasibility to study ultra-high energy neutrinos based on the Earth-skimming technique, by detecting the charged leptons produced in neutrino-nucleon interactions in a high mass target. We propose to detect the charged leptons, or their decay products, with the High Altitude Water Cherenkov (HAWC) observatory, and use as a large mass target for the neutrino interactions the Pico de Orizaba volcano, the highest mountain in Mexico. In this work we develop an estimate of the detection rate using a geometrical model to calculate the effective area of the observatory. Our results show that it may be feasible to perform measurements of the ultra-high energy neutrino flux from cosmic origin during the expected lifetime of the HAWC observatory.