Based on 586 $\mathrm{p}{\mathrm{b}}^{-\mathrm{1}}$ of $e^{+}{e}^{-}$ annihilation data collected at a center-of-mass energy of $\sqrt{s}=4.6\mathrm{GeV}$ with the BESIII detector at the BEPCII collider, the absolute branching fraction of ${\mathrm{\Lambda }}_c^{+}\to p{K}_{\mathrm{S}}^0\eta$ decays is measured for the first time to be $\mathcal{B}({\mathrm{\Lambda }}_c^{+}\to p{K}_{\mathrm{S}}^0\eta )=(0.414\pm 0.084\pm 0.028)\text{\%}$, where the first uncertainty is statistical and the second is systematic. The result is compatible with a previous CLEO result on the relative branching fraction $\frac{\mathcal{B}({\mathrm{\Lambda }}_c^{+}\to p{K}_{\mathrm{S}}^0\eta )}{\mathcal{B}({\mathrm{\Lambda }}_c^{+}\to p{K}^{-}{\pi }^{+})}$, and consistent with theoretical predictions of SU(3) flavor symmetry.

中文翻译：

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绝对支链分数的测量 ${\mathrm{\Lambda }}_C^{+}\to p{ķ}_{\mathrm{小号}}^0\eta$ 衰变

基于586 $\mathrm{p}{\mathrm{b}}^{-\mathrm{1个}}$ 的 ${Ë}^{+}{Ë}^{-}$ 在质心能量为时收集的灭数据 $\sqrt{s}=4.6\mathrm{GeV}$ 在BEPCII对撞机上使用BESIII检测器时， ${\mathrm{\Lambda }}_C^{+}\to p{ķ}_{\mathrm{小号}}^0\eta$ 第一次测量衰减 $\mathcal{乙}（{\mathrm{\Lambda }}_C^{+}\to p{ķ}_{\mathrm{小号}}^0\eta ）=（0.414\pm 0.084\pm 0.028）\text{％}$，其中第一个不确定性是统计性的，第二个不确定性是系统性的。该结果与先前相对支化分数的CLEO结果兼容$\frac{\mathcal{乙}（{\mathrm{\Lambda }}_C^{+}\to p{ķ}_{\mathrm{小号}}^0\eta ）}{\mathcal{乙}（{\mathrm{\Lambda }}_C^{+}\to p{ķ}^{-}{\pi }^{+}）}$，并且与SU（3）风味对称性的理论预测一致。