Nonleptonic two-body weak decays of $Λ_b$ in modified MIT bag model

Abstract

We study the nonleptonic two-body weak decays of $Λ_b$ by modifying the MIT bag model without introducing new parameters to construct the momentum eigenstates of the baryons. We find that the branching ratios of $Λ_b^0 \to Λ_c^+ π^-$, $Λ_c^+ K^-$, $p π^-$ and $pK^-$ are $(4.5\pm0.2)\times 10^{-3}$, $(3.4\pm 0.1)\times 10^{-4}$, $(5.0\pm 0.5)\times 10^{-6}$ and $(6.0\pm 0.7) \times 10^{-6}$, which are all well consistent with the current experimental data, respectively. We also explore P and CP asymmetries for the decays of $Λ_b^0 \to p (π^-,K^-)$. In particular, we obtain that the direct CP-violating rate asymmetries in $Λ_b^0 \to p π^-$ and $Λ_b^0 \to p K^-$ are around $-4.4\%$ and $6.7\%$, in comparison with $(-2.5\pm2.9)\%$ and $(-2.5\pm2.2)\%$ from the Particle Data Group in 2020, respectively.