  We report on a search for the pair production of second generation scalar
leptoquarks (LQ_2) in ppbar collisions at the center-of-mass energy sqrt(s) =
1.96 TeV, using data corresponding to an integrated luminosity of 294 +- 19
pb^-1 recorded with the D0 detector. No evidence for a leptoquark signal in the
LQ_2 LQ_2 -> muq muq channel has been observed, and upper bounds on the product
of cross section times branching fraction were set. This yields lower mass
limits of m(LQ_2) > 247 GeV for beta = Br(LQ_2->muq) = 1 and m(LQ_2) > 182 GeV
for beta = 1/2. Combining these limits with previous D0 results, the lower
limits on the mass of a second generation scalar leptoquark are m(LQ_2) > 251
GeV and m(LQ_2) > 204 GeV for beta = 1 and beta = 1/2, respectively.

High Energy Physics - Experiment