Search for relativistic magnetic monopoles with the ANTARES neutrino telescope

Magnetic monopoles are predicted in various unified gauge models and could be produced at intermediate mass scales. Their detection in a neutrino telescope is facilitated by the large amount of light emitted compared to that from muons. This paper reports on a search for upgoing relativistic magnetic monopoles with the ANTARES neutrino telescope using a data set of 116 days of live time taken from December 2007 to December 2008. The one observed event is consistent with the expected atmospheric neutrino and muon background, leading to a 90% C.L. upper limit on the monopole flux between 1.3 × 10−17 and 8.9 × 10−17 cm−2 s−1 sr−1 for monopoles with velocity β ⩾ 0.625.

► Magnetic monopoles are hypothetical particles predicted in unified theories.
► Relativistic monopoles could be detected in a neutrino telescope.
► A search for upgoing monopoles has been performed using 2008 ANTARES data.
► The obtained flux limits are stronger than limits from other experiments.