We report on measurements of differential mu-bbar cross sections,
where the muon is from a semileptonic b decay and the bbar is identified using
precision track reconstruction in jets.  The semidifferential correlated cross
sections d sigma/dE^bbar_T, d sigma/dp^bbar_T, and d sigma/d Sigma
phi(mu-bbar) for p^u_T > 9 GeV/c, |eta^mu| < 0.6, E^bbar_T > 10 GeV,
|eta^bbar| < 1.5 are presented and compared to next-to-leading order QCD
calculations.