Non-leptonic two-body decays of ${\Lambda }_b^0$ in light-front quark model

Abstract

We study the non-leptonic two-body weak decays of ${\Lambda }_b^0\to pM$ with $M=({\pi }^{-},K^{-})$ and $({\rho }^{-},K^{\ast -})$ in the light-front quark model under the generalized factorization ansatz. By considering the Fermi statistic between quarks and determining spin-flavor structures in baryons, we calculate the branching ratios ($\mathcal{B}$s) and CP-violating rate asymmetries (${\mathcal{A}}_{CP}$s) in the decays. Explicitly, we find that $\mathcal{B}({\Lambda }_b^0\to p{\pi }^{-},p{K}^{-})=(4.18\pm 0.15\pm 0.30,5.76\pm 0.88\pm 0.23)\times 10^{-6}$ and ${\mathcal{A}}_{CP}({\Lambda }_b^0\to p{\pi }^{-},p{K}^{-})=(-3.60\pm 0.14\pm 0.14,6.36\pm 0.21\pm 0.18)\%$ in comparison with the data of $\mathcal{B}({\Lambda }_b^0\to p{\pi }^{-},p{K}^{-})=(4.5\pm 0.8,5.4\pm 1.0)\times 10^{-6}$ and ${\mathcal{A}}_{CP}({\Lambda }_b^0\to p{\pi }^{-},p{K}^{-})=(-2.5\pm 2.9,-2.5\pm 2.2)\%$ given by the Particle Data Group, respectively. We also predict that $\mathcal{B}({\Lambda }_b^0\to p{\rho }^{-},p{K}^{\ast -})=(12.13\pm 3.27\pm 0.91,2.58\pm 0.87\pm 0.13)\times 10^{-6}$ and ${\mathcal{A}}_{CP}({\Lambda }_b^0\to p{\rho }^{-},p{K}^{\ast -})=(-3.32\pm 0.00\pm 0.14,19.25\pm 0.00\pm 0.80)\%$, which could be observed by the experiments at LHCb.

Comments: 16 pages, 1 figure, accepted for publication in PLB. arXiv admin note: text overlap with arXiv:2002.10612