Improved experimental limits on the production of magnetic monopoles

We present new limits on low mass accelerator-produced pointlike Dirac magn etic monopoles trapped and bound in matter surrounding the D0 collision reg ion of the Tevatron at Fermilab (experiment E-882). In the context of a Dre ll-Yan mechanism, we obtain cross section Limits for the production of mono poles with magnetic charge values of 1, 2, 3, and 6 times the minimum Dirac charge of the order of picobarns, some 100 times smaller than found in sim ilar previous Fermilab searches. Mass limits inferred from these cross sect ion limits are presented.