Three-body charmless baryonic ${\bar{B}}_s^0$ decays

Abstract

We study for the first time the three-body charmless baryonic decays ${\bar{B}}_s^0\to \bar{p}\Lambda M^{+}(p\bar{\Lambda }{M}^{-})$, with $M=\pi ,K$. We find that the branching ratios of ${\bar{B}}_s^0\to (\bar{p}\Lambda K^{+}$ and $p\bar{\Lambda }{K}^{-})$ and ${\bar{B}}_s^0\to p\bar{\Lambda }{\pi }^{-}$ are $(5.1\pm 1.1)\times 10^{-6}$ and $(2.8\pm 1.5)\times 10^{-7}$, respectively, which agree with recent experimental results reported by the LHCb collaboration. In addition, we derive the relations \mbox{$\mathcal{B}({\bar{B}}_s^0\to \bar{p}\Lambda K^{+})\simeq (f_K/f_{\pi }{)}^2({\tau }_{B_s^0}/{\tau }_{B^0})\mathcal{B}({\bar{B}}^0\to \bar{p}\Lambda {\pi }^{+})$} and $\mathcal{B}({\bar{B}}_s^0\to p\bar{\Lambda }{\pi }^{-})/\mathcal{B}({\bar{B}}_s^0\to p\bar{\Lambda }{K}^{-})\simeq \mathcal{B}(B^{-}\to p\bar{p}{\pi }^{-})/\mathcal{B}(B^{-}\to p\bar{p}{K}^{-})$ to be confronted to future experimental measurements. The fact that all four processes $B_s^0,{\bar{B}}_s^0\to p\bar{\Lambda }{K}^{-},\bar{p}\Lambda K^{+}$ can occur opens the possibility of decay-time-dependent CP violation measurements in baryonic $B$ decays, something that had not been realised before.

Comments: 9 pages, 2 figures