论文标题
$η\toπ^{+}π^{ - } $用kloe实验分支的上限
Upper limit on the $η\toπ^{+}π^{-}$ branching fraction with the KLOE experiment
论文作者
论文摘要
Based on an integrated luminosity of 1.61 fb$^{-1}$ $e^+e^-$ collision data collected with the KLOE detector at DA$Φ$NE, the Frascati $ϕ$-factory, a search for the $P$- and $CP$-violating decay $η\toπ^{+}π^{-}$ has been performed.辐射$ ϕ \ toηγ$衰减被利用以访问$η$梅森。在$π^{+}π^{ - } $不变的质量频谱中未观察到任何信号，并且在90 \％置信度下的分支分数的上限确定为$ {\ MATHCAL B}（η\toπ^{+toπ^{+} {+}π^{ - }π^{ - }） 结果。从这两个测量值的组合中，我们得到$ {\ Mathcal b}（η\toπ^{+}π^{ - }）<4.4 \ times10^{ - 6} $在90 \％置信度下。
Based on an integrated luminosity of 1.61 fb$^{-1}$ $e^+e^-$ collision data collected with the KLOE detector at DA$Φ$NE, the Frascati $ϕ$-factory, a search for the $P$- and $CP$-violating decay $η\toπ^{+}π^{-}$ has been performed. Radiative $ϕ\toηγ$ decay is exploited to access the $η$ mesons. No signal is observed in the $π^{+}π^{-}$ invariant mass spectrum, and the upper limit on the branching fraction at 90\% confidence level is determined to be ${\mathcal B}(η\toπ^{+}π^{-})<4.9\times10^{-6}$, which is approximately three times smaller than the previous KLOE result. From the combination of these two measurements we get ${\mathcal B}(η\toπ^{+}π^{-}) < 4.4\times10^{-6}$ at 90\% confidence level.
