B meson decays to baryons in the diquark model

Abstract

We study B meson decays to two charmless baryons in the diquark model, including strong and electroweak penguins as well as the tree operators. It is shown that penguin operators can enhance $\bar{B}\to {\text{Bb}}_s\overline{\text{Bb}}$ considerably, but affect $\bar{B}\to {\text{Bb}}_1{\overline{\text{Bb}}}_2$ only slightly, where ${\text{Bb}}_{(1,2)}$ and ${\text{Bb}}_s$ are non-strange and strange baryons, respectively. The $\gamma$ dependence of the decay rates due to tree-penguin interference is illustrated. In principle, some of the ${\text{Bb}}_s\overline{\text{Bb}}$ modes could dominate over ${\text{Bb}}_1{\overline{\text{Bb}}}_2$ for $\gamma >90^{\circ }$, but in general the effect is milder than their mesonic counterparts. This is because the $O_6$ operator can only produce vector but not scalar diquarks, while the opposite is true for $O_1$ and $O_4$. Predictions from diquark model are compared to those from the sum rule calculation. The decays $\bar{B}\to {\text{Bb}}_s{\overline{\text{Bb}}}_s$ and inclusive baryonic decays are also discussed.

Comments: 9 pages, 6 figures, Revtex