Using the heavy-quark approximation and factorization, it is shown that ${\mathrm{\Lambda }}_{\mathit{b}}$→${\mathrm{\Lambda }}_{\mathit{c}}$+${\mathrm{\rho }}^{\mathrm{-}}$ has a branching ratio 60% that of ${\mathrm{\Lambda }}_{\mathit{b}}$→${\mathrm{\Lambda }}_{\mathit{c}}$+${\mathrm{\pi }}^{\mathrm{-}}$ and an asymmetry parameter α of -0.9.

• Received 6 November 1990

DOI:https://doi.org/10.1103/PhysRevD.43.3083