Search for Nucleon Decays induced by GUT Magnetic Monopoles with the MACRO Experiment

TL;DR

This paper reports on an experimental search for magnetic monopoles that could induce nucleon decay via catalysis, setting new flux upper limits using the MACRO detector data.

Contribution

It provides the first experimental limits on magnetic monopole flux considering catalysis of nucleon decay in the MACRO experiment.

Findings

New magnetic monopole flux upper limits at ~3×10^{-16} cm^{-2} s^{-1} sr^{-1}

Flux limits depend on the catalysis cross section

Analysis covers monopole velocities between 1.1×10^{-4} and 5×10^{-3}

Abstract

The interaction of a Grand Unification Magnetic Monopole with a nucleon can lead to a barion-number violating process in which the nucleon decays into a lepton and one or more mesons (catalysis of nucleon decay). In this paper we report an experimental study of the effects of a catalysis process in the MACRO detector. Using a dedicated analysis we obtain new magnetic monopole (MM) flux upper limits at the level of $\sim 3\cdot 10^{-16} cm^{-2} s^{-1} sr^{-1}$ for $1.1\cdot 10^{-4} \le |\beta| \le 5\cdot 10^{-3}$, based on the search for catalysis events in the MACRO data. We also analyze the dependence of the MM flux limit on the catalysis cross section.