Results of the Search for Strange Quark Matter and Q-balls with the SLIM   Experiment
  The SLIM experiment at the Chacaltaya high altitude laboratory was sensitive to nuclearites and Q-balls, which could be present in the cosmic radiation as possible Dark Matter components. It was sensitive also to strangelets, i.e. small lumps of Strange Quark Matter predicted at such altitudes by various phenomenological models. The analysis of 427 m^2 of Nuclear Track Detectors exposed for 4.22 years showed no candidate event. New upper limits on the flux of downgoing nuclearites and Q-balls at the 90% C.L. were established. The null result also restricts models for strangelets propagation through the Earth atmosphere. 
S. Cecchini, M. Cozzi, D. Di Ferdinando, M. Errico, F. Fabbri, G.   Giacomelli, R. Giacomelli, M. Giorgini, A. Kumar, J. McD...