Measurement of baryon production in B-meson decay

Using the CLEO detector at the Cornell Electron Storage Ring, we observe B-meson decays to LAMBDA(c)+ and report on improved measurements of inclusive branching fractions and momentum spectra of other baryons. For the inclusive decay BBAR --> LAMBDA(c)+X with LAMBDA(c)+ --> pK--pi+, we find that the product branching fraction B(BBAR --> LAMBDA(c)+X)B(LAMBDA(c)+ --> pK--pi+) = (0.273 +/- 0.051 +/- 0.039)%. Our measured inclusive branching fractions to noncharmed baryons are B(B --> pX) = (8.0 +/- 0.5 +/- 0.3)%, B(B --> LAMBDA-X) = (3.8 +/- 0.4 +/- 0.6)%, and B(B --> XI--X) = (0.27 +/- 0.05 +/- 0.04)%. From these rates and studies of baryon-lepton and baryon-antibaryon correlations in B decays, we have estimated the branching fraction B(BBAR --> LAMBDA(c)+X) to be (6.4 +/- 0.8 +/- 0.8)%. Combining these results, we calculate B(LAMBDA(c)+ --> pK--pi+) to be (4.3 +/- 1.0 +/- 0.8)%.