HiRes Estimates and Limits for Neutrino Fluxes at the Highest Energies

TL;DR

The HiRes experiment measures ultra-high-energy cosmic rays and uses this data to estimate expected cosmogenic neutrino fluxes and set limits on neutrino fluxes at the highest energies, advancing understanding of cosmic ray origins.

Contribution

This paper provides the first estimates of cosmogenic neutrino fluxes based on HiRes data and establishes competitive limits on ultra-high-energy neutrino fluxes.

Findings

Estimated cosmogenic neutrino fluxes from HiRes data.

Set new limits on electron and tau neutrino fluxes.

Correlated cosmic ray spectrum with neutrino production models.

Abstract

The High Resolution Fly's Eye Experiment (HiRes) measures cosmic rays (CR) at the highest energies using the air fluorescence technique. As data taking on the Dugway Proving Grounds in Western Utah is finished, the HiRes data are relevant for cosmogenic neutrinos in two different ways. We first use our best fit to the measured HiRes CR spectrum together with a model of the extragalactic CR sources to derive the expected cosmogenic neutrino and gamma ray fluxes at Earth. We then use the HiRes data directly to set competitive experimental limits on the electron and tau neutrino fluxes at the highest energies.