  We report on a search for second generation leptoquarks LQ_2 which decay into
a muon plus quark in p\bar{p} collisions at a center-of-mass energy of sqrt{s}
= 1.96 TeV in the D0 detector using an integrated luminosity of about 300 pb-1.
No evidence for a leptoquark signal is observed and an upper bound on the
product of the cross section for single leptoquark production times branching
fraction beta into a quark and a muon was determined for second generation
scalar leptoquarks as a function of the leptoquark mass. This result has been
combined with a previously published D0 search for leptoquark pair production
to obtain leptoquark mass limits as a function of the leptoquark-muon-quark
coupling, lambda. Assuming lambda=1, lower limits on the mass of a second
generation scalar leptoquark are m{LQ_2}>274 GeV and m{LQ_2}>226 GeV for beta=1
and beta=1/2, respectively.
