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...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.展开更多
In this study,we consider all P-wave Ω_(b) states represented by interpolating currents with a derivative and calculate the corresponding masses and pole residues using the QCD sum rule method.Because of the large un...In this study,we consider all P-wave Ω_(b) states represented by interpolating currents with a derivative and calculate the corresponding masses and pole residues using the QCD sum rule method.Because of the large uncertainties in our calculation compared with the small difference in the masses of the excited Ω_(b) states observed by the LHCb collaboration,it is necessary to study other properties of the P-wave Ω_(b) states represented by the interpolating currents investigated in the present work to gain a better understanding of the four excited Ω_(b) states observed by the LHCb collaboration.展开更多
文摘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.
基金Supported by the National Natural Science Foundation of China(11675263)。
文摘In this study,we consider all P-wave Ω_(b) states represented by interpolating currents with a derivative and calculate the corresponding masses and pole residues using the QCD sum rule method.Because of the large uncertainties in our calculation compared with the small difference in the masses of the excited Ω_(b) states observed by the LHCb collaboration,it is necessary to study other properties of the P-wave Ω_(b) states represented by the interpolating currents investigated in the present work to gain a better understanding of the four excited Ω_(b) states observed by the LHCb collaboration.
