We study the non-leptonic two-body weak decays of Λ + c (2286) → B n M with B n (M ) representing as the baryon (meson) states. Based on the SU (3) flavor symmetry, we can describe most of the data reexamined by the BESIII Collaboration with higher precisions. However, our result of B(Λ + c → pπ 0 ) = (5.6 ± 1.5) × 10 −4 is larger than the current experimental limit of 3 × 10 −4 (90% C.L.) by BESIII. In addition, we find that× 10 −4 , which are accessible to the BESIII experiments.

We first study the charmless two-body Λ b decays with the scalar mesons as the final states and predict that B(Λ b → Λf 0 (980, 1500)) = (2.9±0.7, 12.4±3.8)×10 −6 and B(Λ b → pK * − 0 (800, 1430)) = (1.9±0.5, 14.1±4.5)×10 −6 . With the resonant f 0 (980, 1500)2 ± 1.0, 3.5 ± 0.7) × 10 −6 and B(Λ b → pK 0 π − ) = (10.4 ± 2.9) × 10 −6 , in comparison with the data of (4.6 ± 1.9, 15.9 ± 2.6) × 10 −6 and

We examine the constraints imposed by reparametrization invariance on heavy-baryon chiral perturbation theory (HBChPT). We study the case of 3 flavors and consider both the strong and weak ($|\Delta S| =1$) interaction sector. Some of the parameters in the HBChPT Lagrangian are fixed as a consequence of reparametrization invariance. We discuss the consequences for the calculation of hyperon weak radiative decays in HBChPT.Comment: 8 pages, Latex, no figure

We investigate the leading-order amplitudes for weak radiative decays of hyperons in chiral perturbation theory. We consistently include contributions from the next-to-leading order weak-interaction Lagrangian. It is shown that due to these terms Hara's theorem is violated. The data for the decays of charged hyperons can be easily accounted for. However, at this order in the chiral expansion, the four amplitudes for the decays of neutral hyperons satisfy relations which are in disagreement with the data. The asymmetry parameters for all the decays can not be accounted for without higher-order terms. We shortly comment on the effect of the 27-plet part of the weak interaction.Comment: 8 pages of REVTeX and using macro-package "feynman.tex" (available at http://xxx.lanl.gov/ftp/hep-ph/papers/macros) for the 2 figure

We study the charmless two-body b → (φ, η ( ) ) and three-body b → K + K − decays. We obtain B( b → φ) = (3.53 ± 0.24) × 10 −6 to agree with the recent LHCb measurement. However, we find that B( b → η ), given by the previous study.