Search for Subrelativistic Particles with the AMANDA Neutrino Telescope

Abstract: AMANDA is a neutrino telescope situated at the geographical South Pole. The detection method is based on Cherenkov radiation from muons that are created when muon neutrinos collide with atomic nuclei near the detector. The main part of the detector is an array of 677 PMT in the ice at a depth of 1500 - 2000 m. A search in AMANDA data for subrelativistic particles in the velocity range 0.0032 - 0.032 in units of the light speed is presented here. Supermassive particles like magnetic monopoles, Q-balls and nuclearites may emit light at subrelativistic velocities through different suggested mechanisms. One of them is nucleon decay catalysis by magnetic monopoles, where the decay products would emit Cherenkov radiation along a monopole trajectory. A similar process has been suggested for electrically neutral Q-balls. The emitted light from secondary relativistic particles could make monopoles and neutral Q-balls visible to the AMANDA neutrino telescope. Nuclearites and charged Q-balls might become visible by causing a thermal shock along their trajectories, emitting blackbody radiation. In our analysis, two events passed the data filter. This result was consistent with the expected background of 1.15 events. For magnetic monopoles and neutral Q-balls, the resulting upper flux limits based on a detector livetime of 64 days are of the order of 10-16cm-2s-1sr-1. The luminosity of nuclearites and charged Q-balls was found to be too uncertain for expressing the limits as functions of their properties.