Abstract:
We present the first observation of the baryon decay Lambdab0-->Lambdac+pi- followed by Lambdac+-->pK-pi+ in 106 pb-1 p[overline p] collisions at sqrt(s)=1.96 TeV in the CDF experiment. In order to reduce systematic error, the measured rate for Lambdab0 decay is normalized to the kinematically similar meson decay [overline B]0-->D+pi- followed by D+-->pi+K-pi+. We report the ratio of production cross sections (sigma) times the ratio of branching fractions ([script B]) for the momentum region integrated above pT>6 GeV/c and pseudorapidity range |eta|<1.3: sigma(p[overline p]-->Lambdab0X)/sigma(p[overline p]-->[overline B]0X)×[script B](Lambdab0-->Lambdac+pi-)/[script B]([overline B]0-->D+pi-)=0.82$\pm$ 0.08(stat)$\pm$0.11(syst)$\pm$0.22[[script B](Lambdac+-->pK-pi+)].