Horizontal Muons and a Search for AGN Neutrinos in Soudan 2

TL;DR

This paper measures the flux of horizontal neutrino-induced muons in Soudan 2 and sets limits on AGN neutrino fluxes based on the absence of high-energy muons, contributing to neutrino astronomy and astrophysics.

Contribution

It provides the first measurement of horizontal muon flux in Soudan 2 and establishes new upper limits on AGN neutrino emissions.

Findings

Measured horizontal muon flux: 4.01±0.50±0.30×10^{-13} cm^{-2} sr^{-1} s^{-1}

No significant high-energy muons detected, leading to flux limits for AGN neutrinos

Constraints improve understanding of neutrino flux from astrophysical sources

Abstract

We measure the horizontal ($|\cos(\theta_z)|<0.14$) neutrino-induced muon flux in Soudan 2 to be $4.01\pm 0.50\pm 0.30\times 10^{-13} $cm$^{-2}$sr$^{-1}$s$^{-1}$. From the absence of horizontal muons with large energy loss, we set a limit on the flux of muon neutrinos from Active Galactic Nuclei.