利用CLEO-c探测器在Ds ~*+ Ds ~-产生能Ecm = 4170 MeV附近收集的数据，研究了Ds ~+介子衰变为两个赝标介子的过程.我们报告的搜索单Cabibbo抑制Ds+衰变模式K+ eta，K+ eta '，pi+ K 0 S，K+ pi 0，和同位旋禁止的衰变模式Ds+到pi+ pi 0。我们相对于Cabibbo偏好的Ds+模式pi+ eta、pi+ eta '和K+ KoS进行归一化，并获得分支分数的比率：Ds+至K+ eta / Ds+至pi+ eta =（8.9 +-1.5 +-0.4）%，Ds+对K+ eta' / Ds+对pi+ eta' =（4.2 +-1.3 +-0.3）%，Ds+至pi+ K 0 S/ Ds+至K+ K 0 S =（8.2 +- 0.9 +- 0.2）%，Ds+至K+ pi 0/ Ds+至K+ K 0 S =（5.0 +- 1.2 +- 0.6）%，Ds+至pi+ pi 0/ Ds+至K+ K 0 S < 4.1%（90% CL），其中不确定度分别为统计和系统不确定度。
英文摘要：
Using data collected near the Ds*+ Ds- peak production energy Ecm = 4170 MeV by the CLEO-c detector, we study the decays of Ds+ mesons to two pseudoscalar mesons. We report on searches for the singly-Cabibbo-suppressed Ds+ decay modes K+ eta, K+ eta', pi+ K0S, K+ pi0, and the isospin-forbidden decay mode Ds+ to pi+ pi0. We normalize with respect to the Cabibbo-favored Ds+ modes pi+ eta, pi+ eta', and K+ K0S, and obtain ratios of branching fractions: Ds+ to K+ eta / Ds+ to pi+ eta = (8.9 +- 1.5 +- 0.4)%, Ds+ to K+ eta' / Ds+ to pi+ eta' = (4.2 +- 1.3 +- 0.3)%, Ds+ to pi+ K0S / Ds+ to K+ K0S = (8.2 +- 0.9 +- 0.2)%, Ds+ to K+ pi0 / Ds+ to K+ K0S = (5.0 +- 1.2 +- 0.6)%, and Ds+ to pi+ pi0 / Ds+ to K+ K0S < 4.1% at 90% CL, where the uncertainties are statistical and systematic, respectively.
Study of the $ρ$ and $ω$ meson decays into pseudoscalar meson and $e^+e^-$ pair with the CMD-2 detector
用CMD-2探测器在720 - 840 MeV厘米级收集的3.3 pb $^{-1}$数据，计算了1000 μ m ~（-1）μ m ~（-1）μ m ~（能量范围内，转换衰变$ω\toπ^0e^+e^-$的分支分数已被测量：$\mathcal{B}(ω\toπ^0e^+e^-)=(8.19\pm0.71\pm0.62)\cdot10^{-4}$。在90%置信水平下获得了以下转换衰变的分支分数的上限：$\mathcal{B}(ρ\toπ^0e^+e^-)<1.6\cdot10^{-5}$、$\mathcal{B}(ρ\toηe^+e^-)<0.7\cdot10^{-5}$和$\mathcal{B}(ω\toηe^+e^-)<1.1\cdot10^{-5}$。
