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

Abstract

We study the charmless two-body decays of $b$-baryons $(Λ_b$, $Ξ_b^-$, $Ξ_b^0)$. We find that ${\cal B}(Ξ_b^-\to Λρ^-)=(2.08^{+0.69}_{-0.51})\times 10^{-6}$ and ${\cal B}(Ξ_b^0\to Σ^+ M^-)=(4.45^{+1.46}_{-1.09},11.49^{+3.8}_{-2.9},4.69^{+1.11}_{-0.79},2.98^{+0.76}_{-0.51})\times 10^{-6}$ for $M^-=(π^-,ρ^-,K^-,K^{*-})$, which are compatible to ${\cal B}(Λ_b\to p π^-,p K^-)$. We also obtain that ${\cal B}(Λ_b\to Λω)=(2.30\pm0.10)\times 10^{-6}$, ${\cal B}(Ξ_b^-\toΞ^- ϕ,Ξ^- ω)\simeq {\cal B}(Ξ_b^0\toΞ^0 ϕ,Ξ^0 ω)=(5.35\pm0.41,3.65\pm0.16)\times 10^{-6}$ and ${\cal B}(Ξ^-_b\toΞ^{-} η^{(\prime)})\simeq {\cal B}(Ξ^0_b\to Ξ^0 η^{(\prime)})=(2.51^{+0.70}_{-0.46},2.99^{+1.16}_{-0.57})\times 10^{-6}$. For the CP violating asymmetries, we show that ${\cal A}_{CP}(Λ_b\to p K^{*-})={\cal A}_{CP}(Ξ_b^-\to Σ^0(Λ)K^{*-})={\cal A}_{CP}(Ξ_b^0\to Σ^+K^{*-})=(19.7\pm 1.4)\%$. Similar to the charmless two-body $Λ_b$ decays, the $Ξ_b$ decays are accessible to the LHCb detector.

13 pages, no figure, version accepted by PRD