Search for $\overrightarrow{B}\overline{p}{e}^{-}{\overline{\nu }}_{e}X$ decay using a partial reconstruction method

Using data collected on the ${\rm Y}\mathrm{}\left(4S\right)\mathrm{}$ resonance and the nearby continuum by the CLEO detector at the Cornell Electron Storage Ring, we have searched for the semileptonic decay of B mesons to $e\overline{p}$ inclusive final states. We obtain an upper limit for $\overrightarrow{b}c$ decays of $\mathcal{B}\left(\overrightarrow{B}\overline{p}{e}^{-}{\overline{\nu }}_{e}X\right)<\mathrm{}5.9\mathrm{}\times {10}^{-4}.$ For the $\overrightarrow{b}u$ decay, we find an upper limit of $\mathcal{B}{(B}^{-}\to p\overline{p}{e}^{-}{\overline{\nu }}_e)<\mathrm{}1.2\mathrm{}\times {10}^{-3}$ based on a $V-A$ model, while a phase space model gives an upper limit of $\mathcal{B}{(B}^{-}\to p\overline{p}{e}^{-}{\overline{\nu }}_e)<\mathrm{}5.2\mathrm{}\times {10}^{-3}.$ All upper limits are measured at the 90% confidence level.