We study the three-body baryonic $B\to { \bf B\bar B'}M$ decays with $M$ representing the $\eta$ or $\eta'$ meson. Particularly, we predict that ${ \cal B}(B^-\to\Lambda\bar p\eta,\Lambda\bar p\eta')=(5.3\pm 1.4,3.3\pm 0.7)\times 10^{ -6}$ or $(4.0\pm 0.7,4.6\pm 1.1)\times 10^{ -6}$, where the errors arise from the non-factorizable effects as well as the uncertainties in the $0\to { \bf B\bar B'}$ and $B\to{ \bf B\bar B'}$ transition form factors, while the two different results are due to overall relative signs between the form factors, causing the constructive and destructive interference effects. For the corresponding baryonic $\bar B_s^0$ decays, we find that ${ \cal B}(\bar B^0_s\to \Lambda\bar \Lambda \eta,\Lambda\bar \Lambda \eta')=(1.2\pm 0.3,2.6\pm 0.8)\times 10^{ -6}$ or $(2.1\pm 0.6,1.5\pm 0.4)\times 10^{ -6}$ with the errors similar to those above. The decays in question are accessible to the experiments at BELLE and LHCb.
Categories: hep-ph hep-ex