Charmless two-body anti-triplet $b$-baryon decays

Abstract

We study the charmless two-body decays of $b$-baryons $({\Lambda }_b$, ${\Xi }_b^{-}$, ${\Xi }_b^0)$. We find that $\mathcal{B}({\Xi }_b^{-}\to \Lambda {\rho }^{-})=(2.08_{-0.51}^{+0.69})\times 10^{-6}$ and $\mathcal{B}({\Xi }_b^0\to {\Sigma }^{+}{M}^{-})=(4.45_{-1.09}^{+1.46},11.49_{-2.9}^{+3.8},4.69_{-0.79}^{+1.11},2.98_{-0.51}^{+0.76})\times 10^{-6}$ for $M^{-}=({\pi }^{-},{\rho }^{-},K^{-},K^{\ast -})$, which are compatible to $\mathcal{B}({\Lambda }_b\to p{\pi }^{-},p{K}^{-})$. We also obtain that $\mathcal{B}({\Lambda }_b\to \Lambda \omega )=(2.30\pm 0.10)\times 10^{-6}$, $\mathcal{B}({\Xi }_b^{-}\to {\Xi }^{-}\varphi ,{\Xi }^{-}\omega )\simeq \mathcal{B}({\Xi }_b^0\to {\Xi }^0\varphi ,{\Xi }^0\omega )=(5.35\pm 0.41,3.65\pm 0.16)\times 10^{-6}$ and $\mathcal{B}({\Xi }_b^{-}\to {\Xi }^{-}{\eta }^{(\prime )})\simeq \mathcal{B}({\Xi }_b^0\to {\Xi }^0{\eta }^{(\prime )})=(2.51_{-0.46}^{+0.70},2.99_{-0.57}^{+1.16})\times 10^{-6}$. For the CP violating asymmetries, we show that ${\mathcal{A}}_{CP}({\Lambda }_b\to p{K}^{\ast -})={\mathcal{A}}_{CP}({\Xi }_b^{-}\to {\Sigma }^0(\Lambda )K^{\ast -})={\mathcal{A}}_{CP}({\Xi }_b^0\to {\Sigma }^{+}{K}^{\ast -})=(19.7\pm 1.4)\%$. Similar to the charmless two-body ${\Lambda }_b$ decays, the ${\Xi }_b$ decays are accessible to the LHCb detector.

Comments: 13 pages, no figure, version accepted by PRD