论文标题
观察$ψ（3770）\toηj/ψ$
Observation of $ψ(3770)\toηJ/ψ$
论文作者
论文摘要
该过程的诞生横截面$ e^+e^ - \toηj/ψ$在质量中心$ \ sqrt {s} = 3.773〜 \ mathrm {gev} $的衡量为（$ 8.89 \ pm0.88 \ pm0.88 \ pm0.42 $ pm0.42 $）$〜\ mathrm { BEPCII存储环。首次观察到衰减$ψ（3770）\rightArrowηj/ψ$，统计意义为$7.4σ$。从$ e^+e^ - \ toηj/ψ$从$ \ sqrt {s} = 3.773 $到$ 4.600〜 \ mathrm {gev} $从$ e^+e^ - \toηj/ψ$的衣服横截面线形状。 $（11.6 \ pM6.1 \ pm1.0）\ times 10^{ - 4} $当$ψ（3770）$衰减幅度连贯地添加到其他贡献中，而$（7.9 \ pm1.0 \ pm0.7）\ times 10^{ - 4} $ 10^{ - 4} $添加了添加时。在这里，第一个不确定性是统计的，第二个是系统的。
The Born cross section of the process $e^+e^-\toηJ/ψ$ at a center-of-mass energy $\sqrt{s}=3.773 ~\mathrm{GeV}$ is measured to be ($8.89\pm0.88\pm0.42$)$~\mathrm{pb}$, using a data sample collected with the BESIII detector operating at the BEPCII storage ring. The decay $ψ(3770)\rightarrowηJ/ψ$ is observed for the first time with a statistical significance of $7.4σ$. From a fit to the dressed cross-section line-shape of $e^+e^-\toηJ/ψ$ from $\sqrt{s}=3.773$ to $4.600~\mathrm{GeV}$ we obtain the branching fraction of the decay $ψ(3770)\to ηJ/ψ$ to be $(11.6\pm6.1\pm1.0)\times 10^{-4}$ when the $ψ(3770)$ decay amplitude is added coherently to the other contributions, and $(7.9\pm1.0\pm0.7)\times 10^{-4}$ when it is added incoherently. Here the first uncertainties are statistical and the second are systematic.
