Using the perturbative QCD approach,we studied the effects of the hadronic structure of photons on the pure annihilation rediative decays B→φγ and B_(s)→(ρ^(0),ω)γ.These decays have small branching fractions du...Using the perturbative QCD approach,we studied the effects of the hadronic structure of photons on the pure annihilation rediative decays B→φγ and B_(s)→(ρ^(0),ω)γ.These decays have small branching fractions due to the power suppression by Λ/mB,which makes them very sensitive to next-leading power corrections.The quark components and the related two-particle distribution amplitudes of a final state photon are introduced.The branching fractions can be enhanced remarkably by factorizable and nonfactorizable emission diagrams.The branching fraction of B→φγ increases by approximately 40 times,and those of B_(s)→ρ^(0)γ and B_(s)→ωγ are on the order of O(10-10).We also note that the ratio of branching fractions of B_(s)→ρ^(0)γ and B_(s)→ωγ is very sensitive to the effects of the hadronic structure of photons.All these results can be tested in future.展开更多
In this study,we calculate the transition form factors of Λ_(b) decaying into Λ_(c) within the framework of light-cone sum rules with the distribution amplitudes(DAs)of the Λ_(b)-baryon.In the hadronic representati...In this study,we calculate the transition form factors of Λ_(b) decaying into Λ_(c) within the framework of light-cone sum rules with the distribution amplitudes(DAs)of the Λ_(b)-baryon.In the hadronic representation of the correlation function,we isolate both the Λ_(c) and Λ_(c)^(∗) states so that the Λ_(b)→Λ_(c) form factors can be obtained without ambiguity.We investigate the P-type and A-type currents to interpolate light baryons for comparison because the interpolation current for the baryon state is not unique.We also employ three parametrization models for the DAs of Λ_(b) in the numerical calculation.We present the numerical predictions for the Λ_(b)→Λ_(c) form factors and branching fractions,averaged forward-backward asymmetry,averaged final hadron polarization,and averaged lepton polarization of the Λ_(b)→Λ_(c)ℓμ decays,as well as the ratio of the branching ratios RΛ_(c).The predicted RΛ_(c) is consistent with LHCb data.展开更多
基金Supported in part by the Open Project of Shaanxi Collaborative Innovation Center of Industrial Auxiliary Chemistry & Technology (XTKF-2020-01)the Nation-al Science Foundation of China (11705159,11975195)+1 种基金the Natural Science Foundation of Shandong province (ZR2019JQ04,ZR2022ZD26,ZR2020MA093)the Project of Shandong Province Higher Educational Science and Technology Program (2019KJJ007)。
文摘Using the perturbative QCD approach,we studied the effects of the hadronic structure of photons on the pure annihilation rediative decays B→φγ and B_(s)→(ρ^(0),ω)γ.These decays have small branching fractions due to the power suppression by Λ/mB,which makes them very sensitive to next-leading power corrections.The quark components and the related two-particle distribution amplitudes of a final state photon are introduced.The branching fractions can be enhanced remarkably by factorizable and nonfactorizable emission diagrams.The branching fraction of B→φγ increases by approximately 40 times,and those of B_(s)→ρ^(0)γ and B_(s)→ωγ are on the order of O(10-10).We also note that the ratio of branching fractions of B_(s)→ρ^(0)γ and B_(s)→ωγ is very sensitive to the effects of the hadronic structure of photons.All these results can be tested in future.
基金Supported in part by the National Natural Science Foundation of China(12175218,11975112)the Natural Science Foundation of Shandong province with(ZR2020MA093)supported by the National Natural Science Foundation of China(12147118)。
文摘In this study,we calculate the transition form factors of Λ_(b) decaying into Λ_(c) within the framework of light-cone sum rules with the distribution amplitudes(DAs)of the Λ_(b)-baryon.In the hadronic representation of the correlation function,we isolate both the Λ_(c) and Λ_(c)^(∗) states so that the Λ_(b)→Λ_(c) form factors can be obtained without ambiguity.We investigate the P-type and A-type currents to interpolate light baryons for comparison because the interpolation current for the baryon state is not unique.We also employ three parametrization models for the DAs of Λ_(b) in the numerical calculation.We present the numerical predictions for the Λ_(b)→Λ_(c) form factors and branching fractions,averaged forward-backward asymmetry,averaged final hadron polarization,and averaged lepton polarization of the Λ_(b)→Λ_(c)ℓμ decays,as well as the ratio of the branching ratios RΛ_(c).The predicted RΛ_(c) is consistent with LHCb data.