测量$Ξ_c(2645)$和$Ξ_c(2815)$重子的质量，观测$Ξ_c(2980)\toΞ_c(2645)π$ %，观测$Ξ_c(2980)$，观测$Ξ_c(2980)\to Ξ_c(2645)π$
Measurement of masses of the $Ξ_c(2645)$ and $Ξ_c(2815)$ baryons and observation of $Ξ_c(2980)\toΞ_c(2645)π$ %and observation of the $Ξ_c(2980)$ and observation of $Ξ_c(2980)\to Ξ_c(2645)π$
摘要：
我们报告的$Ξ_c(2645)$和$Ξ_c(2815)$重子的质量的精确测量使用的数据样本414 FB $^{-1}$收集的Belle合作在KEKB $e^+ e^-$对撞机。在$Ξ_c^{+,0}π^{-,+}$衰变模式中观察到$Ξ_c(2645)^{0,+}$态，而在$Ξ_c(2645)^{+,0}π^{-,+}$衰变模式中重建$Ξ_c(2815)^{0,+}$态。测定了以下质量分裂：$m_{Ξ_c(2645)^+} - m_{Ξ_c(2645)^0} = (-0.1 \pm 0.3 ({\rm stat}) \pm 0.6 {(\rm syst})) {\rm MeV}/{\rm c}^2$和$m_{Ξ_c(2815)^+} - m_{Ξ_c(2815)^0} = (-3.4 \pm 1.9 ({\rm stat}) \pm 0.9 {(\rm syst})) {\rm MeV}/{\rm c}^2$，其精度比当前世界平均值高得多。我们还观察到一个新的衰变模式，$Ξ_c(2980)^{0,+} \to Ξ_c(2645)^{+,0}π^{-,+}$。
英文摘要：
We report a precise measurement of the masses of the $Ξ_c(2645)$ and $Ξ_c(2815)$ baryons using a data sample of 414 fb$^{-1}$ collected by the Belle collaboration at the KEKB $e^+ e^-$ collider. The states $Ξ_c(2645)^{0,+}$ are observed in the $Ξ_c^{+,0}π^{-,+}$ decay modes, while the $Ξ_c(2815)^{0,+}$ are reconstructed in the $Ξ_c(2645)^{+,0}π^{-,+}$ decay modes. The following mass splittings are determined: $m_{Ξ_c(2645)^+} - m_{Ξ_c(2645)^0} = (-0.1 \pm 0.3 ({\rm stat}) \pm 0.6 {(\rm syst})) {\rm MeV}/{\rm c}^2$ and $m_{Ξ_c(2815)^+} - m_{Ξ_c(2815)^0} = (-3.4 \pm 1.9 ({\rm stat}) \pm 0.9 {(\rm syst})) {\rm MeV}/{\rm c}^2$ with a much better precision than the current world averages. We also observe a new decay mode, $Ξ_c(2980)^{0,+} \to Ξ_c(2645)^{+,0}π^{-,+}$.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
