Nonleptonic two-body weak decays of ${\Lambda }_b$ in modified MIT bag model

Abstract

We study the nonleptonic two-body weak decays of ${\Lambda }_b$ 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 ${\Lambda }_b^0\to {\Lambda }_c^{+}{\pi }^{-}$, ${\Lambda }_c^{+}{K}^{-}$, $p{\pi }^{-}$ and $p{K}^{-}$ are $(4.5\pm 0.2)\times 10^{-3}$, $(3.4\pm 0.1)\times 10^{-4}$, $(5.0\pm 0.5)\times 10^{-6}$ 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 ${\Lambda }_b^0\to p({\pi }^{-},K^{-})$. In particular, we obtain that the direct CP-violating rate asymmetries in ${\Lambda }_b^0\to p{\pi }^{-}$ and ${\Lambda }_b^0\to p{K}^{-}$ are around $-4.4\%$ and $6.7\%$, in comparison with $(-2.5\pm 2.9)\%$ and $(-2.5\pm 2.2)\%$ from the Particle Data Group in 2020, respectively.

Comments: 16 pages, no figure, revised version accepted by PRD