Determination of $\mathrm{\mid }{V}_{ub}\mathrm{\mid }$ from exclusive baryonic $B$ decays

We use the exclusive baryonic $B$ decays to determine the Cabibbo-Kobayashi-Maskawa (CKM) matrix element $V_{ub}$. From the relation $\mathrm{\mid }{V}_{ub}{\mathrm{\mid }}^2\mathrm{/}\mathrm{\mid }{V}_{cb}{\mathrm{\mid }}^2=({\mathcal{B}}_{\pi }\mathrm{/}{\mathcal{B}}_D){\mathcal{R}}_{ff}$ based on $B^-\to p\bar p \pi^-$and$\bar B^0\to p\bar p D^0$decays,where$|V_{cb}|$and${\cal B}\pi/{\cal B}D\equiv{\cal B}(B^-\to p\bar p \pi^-)/{\cal B}(\bar B^0\to p\bar p D^0)$arethedatainputparameters,while${\cal R}{ff}$ is the one fixed by the $B\to p\bar{p}$ transition matrix elements, we find $\mathrm{\mid }{V}_{ub}\mathrm{\mid }=(3.48_{-0.63}^{+0.87}\pm 0.40\pm 0.07)\times {10}^{-3}$ with the errors corresponding to the uncertainties from ${\mathcal{R}}_{ff}$, ${\cal B}\pi/{\cal B}D$and$|V{cb}|$, respectively. Being independent of the previous results, our determination of $\mathrm{\mid }{V}_{ub}\mathrm{\mid }$ has the central value close to those from the exclusive $\bar{B}\to \pi \mathrm{\ell }{\bar{\nu }}_{\mathrm{\ell }}$ and $\Lambda_b\to p\mu^-\bar \nu_\mu$decays,butoverlapstheonefromtheinclusive$\bar B\to X_u \ell\bar \nu_\ell$withthecurrentuncertainties\mathrm{.}Theextractionof$|V_{ub}|$inthebaryonic$B$ decays is clearly very useful for the complete determination of the CKM matrix elements as well as the exploration of new physics.