Ultra-Relativistic Magnetic Monopole Search with the ANITA-II Balloon-borne Radio Interferometer

TL;DR

This paper reports a search for ultra-relativistic magnetic monopoles using the ANITA-II balloon experiment, setting the most stringent upper limits to date on their flux at extremely high energies.

Contribution

It presents the first extensive search for relativistic magnetic monopoles with balloon-borne radio detection, establishing new upper flux limits at ultra-high energies.

Findings

No monopole candidates detected in 31 days of data.

Established a 90% confidence level upper limit on monopole flux of ~10^{-19}/(cm^2-s-sr).

Set the strongest limits to date for monopoles with Lorentz boost factors around 10^{10}.

Abstract

We have conducted a search for extended energy deposition trails left by ultra-relativistic magnetic monopoles interacting in Antarctic ice. The non-observation of any satisfactory candidates in the 31 days of accumulated ANITA-II flight data results in an upper limit on the diffuse flux of relativistic monopoles. We obtain a 90% C.L. limit of order 10^{-19}/(cm^2-s-sr) for values of Lorentz boost factor 10^{10}<gamma at the anticipated energy E=10^{16} GeV. This bound is stronger than all previously published experimental limits for this kinematic range.