Search forΛb→JψΛ0inpp¯collisions ats=1.8TeV

We have searched for the $b$-flavored baryon decay ${\ensuremath{\Lambda}}_{b}\ensuremath{\rightarrow}\frac{J}{\ensuremath{\psi}}{\ensuremath{\Lambda}}^{0}$ in $p\overline{p}$ collisions at $\sqrt{s}=1.8$ TeV with the Collider Detector at Fermilab (CDF). In the $\frac{J}{\ensuremath{\psi}}{\ensuremath{\Lambda}}^{0}$ invariant-mass distribution we observe a flat distribution and a small number of events, consistent with no signal. Using the $b$-quark cross section measured by the CDF we put an upper limit on the $b\ensuremath{\rightarrow}{\ensuremath{\Lambda}}_{b}$ production fraction times the branching ratio $F({\ensuremath{\Lambda}}_{b})B({\ensuremath{\Lambda}}_{b}\ensuremath{\rightarrow}\frac{J}{\ensuremath{\psi}}{\ensuremath{\Lambda}}^{0})$ of 0.50\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}3}$ at 90% confidence level.