Measurement of sigma_Lambda0(b)/sigma B-bar0 x B(Lambda0(b) --> Lambda+_c pi+-)/B(B0 --> D+ pi+-) in p anti-p Collisions at s**(1/2) = 1.96 TeV

We present the first observation of the baryon decay Λb0→ Λc+π- followed by Λc+→pK-π+ in 106pb-1 pp̄ collisions at s=1.96TeV in the CDF experiment. In order to reduce systematic error, the measured rate for Λb0 decay is normalized to the kinematically similar meson decay B̄0→D+π- followed by D+→π+K-π+. We report the ratio of production cross sections (σ) times the ratio of branching fractions (B) for the momentum region integrated above pT>6GeV/c and pseudorapidity range |η