The underground Soudan-1 nucleon decay experiment can measure the velocities of slowly moving particles if they can be detected by ionization at a level 0.5 times that of a relativistic muon. Magnetic monopoles predicted by grand unified theories should satisfy this condition if their velocities are greater than 10-3c. During a live time of 0.41 yr, no candidate has been observed, implying a 90%-confidence-level limit on the flux of such objects of <4.1×10-13 cm-2 sr-1 s-1 for velocities between 10-3c and 10-2c.
ASJC Scopus subject areas
- Physics and Astronomy(all)