Hadronic B Decays to Charmed Baryons

Abstract

We study exclusive B decays to final states containing a charmed baryon within the pole model framework. Since the strong coupling for ${\Lambda }_b\bar{B}N$ is larger than that for ${\Sigma }_b\bar{B}N$, the two-body charmful decay $B^{-}\to {\Sigma }_c^0\bar{p}$ has a rate larger than ${\bar{B}}^0\to {\Lambda }_c^{+}\bar{p}$ as the former proceeds via the ${\Lambda }_b$ pole while the latter via the ${\Sigma }_b$ pole. By the same token, the three-body decay ${\bar{B}}^0\to {\Sigma }_c^{++}\bar{p}{\pi }^{-}$ receives less baryon-pole contribution than $B^{-}\to {\Lambda }_c^{+}\bar{p}{\pi }^{-}$. However, because the important charmed-meson pole diagrams contribute constructively to the former and destructively to the latter, ${\Sigma }_c^{++}\bar{p}{\pi }^{-}$ has a rate slightly larger than ${\Lambda }_c^{+}\bar{p}{\pi }^{-}$. It is found that one quarter of the $B^{-}\to {\Lambda }_c^{+}\bar{p}{\pi }^{-}$ rate comes from the resonant contributions. We discuss the decays ${\bar{B}}^0\to {\Sigma }_c^0\bar{p}{\pi }^{+}$ and $B^{-}\to {\Sigma }_c^0\bar{p}{\pi }^0$ and stress that they are not color suppressed even though they can only proceed via an internal W emission.

25 pages, 6 figures