Search for Slow Monopoles and Quarks

A search was made for heavy slow monopoles and quarks in the velocity range from 0.01 to 0.1 light velocity. The detector used is a scintillation counter hodoscope of \(S{·}{=}1.1\) m 2 sr and of depth 21 cm Pb plus 52 cm plastic scintillation total. The absence of candidates during the run time of 3800 hours sets an upper limit, 90% confidence level, of 1.5×10 -11 cm -2 sr -1 sec -1 for magnetic monopoles, 2e/3 quarks, and for e/3 quarks.