Semileptonic $B-\to p\bar{p}\ell -{\bar{\nu }}_{\ell }$ decays

Abstract

We study the four-body exclusive semileptonic baryonic $\bar{B}$ decays of $B^{-}\to p\bar{p}{\ell }^{-}{\bar{\nu }}_{\ell }$ ($\ell =e,\mu ,\tau$) in the standard model. We find that their decay branching ratios are about $(1.0,1.0,0.5)\times 10^{-4}$, respectively. In particular, the electron mode is close to the corresponding CLEO's upper limit of $5.2\times 10^{-3}$, while all results are about one or two orders of magnitude larger than the previous estimated values for the inclusive modes of $\bar{B}\to \mathbf{B}{\bar{\mathbf{B}}}^{\prime }\ell \bar{\nu }$. Clearly, both B-factories of Belle and BaBar should be able to observe these exclusive four-body modes.

Comments: 10 pages, 3 figures, published version