Improved analysis of the rare decay processes of Λ_b

It is noted that in the new Particle Data Group(PDG) version the rare decays of the Λ_b baryon have been revised with more accuracy. The new results show that most of the existing theoretical results on the process Λ_b→Λ_γ Lgbare larger than those of experiments. With the improved higher-order light-cone distribution amplitudes of the Λ baryon, we reanalyze the process in the framework of light-cone quantum chromodynamics sum rules and the branching ratio is estimated to be Br (Λ_b→Λ_γ)=(7.38_(-0.39)~(+0.40))×10~(16), which is consistent with the new experimental result. Furthermore, another process Λ_b→Λl~+l~- is also analyzed in the same frame. The final branching ratio is calculated to be Br (Λ_b→Λl~+l~-)=1.20×10~(-6), which is in good accordance with the data from the PDG and other theoretical predictions.

Improved analysis of the rare decay processes of Λb

It is noted that in the new Particle Data Group (PDG) version the rare decays of the ${{rm{Lambda }}}_{b}$ baryon have been revised with more accuracy. The new results show that most of the existing theoretical results on the process ${{rm{Lambda }}}_{b}to {rm{Lambda }}gamma $ are larger than those of experiments. With the improved higher-order light-cone distribution amplitudes of the Λ baryon, we reanalyze the process in the framework of light-cone quantum chromodynamics sum rules and the branching ratio is estimated to be ${rm{Br}}({{rm{Lambda }}}_{b}to {rm{Lambda }}gamma )=({7.38}_{-0.39}^{+0.40})times {10}^{-6}$, which is consistent with the new experimental result. Furthermore, another process ${{rm{Lambda }}}_{b}to {rm{Lambda }}$ ${l}^{+}{l}^{-}$ is also analyzed in the same frame. The final branching ratio is calculated to be ${rm{Br}}({{rm{Lambda }}}_{b}to {rm{Lambda }}{l}^{+}{l}^{-})=1.20,times ,{10}^{-6}$, which is in good accordance with the data from the PDG and other theoretical predictions.