Semileptonic baryonic $B$ decays

Abstract

We study the semileptonic $B\to \mathbf{B}{\bar{\mathbf{B}}}^{\prime }L{\bar{L}}^{\prime }$ decays with $\mathbf{B}{\bar{\mathbf{B}}}^{\prime }$ ($L{\bar{L}}^{\prime }$) representing a baryon (lepton) pair. Using the new determination of the $B\to \mathbf{B}{\bar{\mathbf{B}}}^{\prime }$ transition form factors, we obtain $\mathcal{B}(B^{-}\to p\bar{p}{\mu }^{-}{\bar{\nu }}_{\mu })=(5.4\pm 2.0)\times 10^{-6}$ agreeing with the current data. Besides, $\mathcal{B}(B^{-}\to \Lambda \bar{p}\nu \bar{\nu })=(3.5\pm 1.0)\times 10^{-8}$ is calculated to be 20 times smaller than the previous prediction. In particular, we predict $\mathcal{B}({\bar{B}}_s^0\to p\bar{\Lambda }{e}^{-}{\bar{\nu }}_e,p\bar{\Lambda }{\mu }^{-}{\bar{\nu }}_{\mu },p\bar{\Lambda }{\tau }^{-}{\bar{\nu }}_{\tau })=(2.1\pm 0.6,2.1\pm 0.6,1.7\pm 1.0)\times 10^{-6}$ and $\mathcal{B}({\bar{B}}_s^0\to \Lambda \bar{\Lambda }\nu \bar{\nu })=(0.8\pm 0.2)\times 10^{-8}$, which can be accessible to the LHCb experiment.

Comments: 14 pages, 4 figures, 3 tables, title changed, published version