Relativistic Magnetic Monopole Flux Constraints from RICE

TL;DR

This paper sets new, stringent upper limits on the flux of relativistic magnetic monopoles using radio detection at the South Pole, surpassing previous experimental bounds significantly.

Contribution

It provides the first strong constraints on relativistic monopole flux at ultra-high energies using radio Cherenkov detection and detailed Monte Carlo simulations.

Findings

95% confidence level upper limit of ~10^{-18}/(cm^2-s-sr)

Over an order of magnitude stronger than previous limits

Monte Carlo simulation including energy losses

Abstract

We report an upper limit on the flux of relativistic monopoles based on the non-observation of in-ice showers by the Radio Ice Cherenkov Experiment (RICE) at the South Pole. We obtain a 95% C.L. limit of order 10^{-18}/(cm^2-s-sr) for intermediate mass monopoles of 10^7<gamma<10^{12} at the anticipated energy E=10^{16} GeV. This bound is over an order of magnitude stronger than all previously published experimental limits for this range of boost parameters gamma, and exceeds two orders of magnitude improvement over most of the range. We review the physics of radio detection, describe a Monte Carlo simulation including continuous and stochastic energy losses, and compare to previous experimental limits.