arXiv 1706.010482017-06-04hep-ex

魅力物理学在BESIII

Charm physics at BESIII

Peter Weidenkaff

备注：: Proceeding of the 52nd Rencontres de Moriond EW 2017, La Thuile, Italy, March 18-25, 2017

摘要：

对至少包含一个粲夸克的介子和重子的研究被称为开粲物理学。这为研究上型夸克跃迁提供了可能。由于$c$夸克不能在任何质量极限下处理，理论预测是困难的，实验输入是至关重要的。BESIII收集了$e^{+}e^{-}$碰撞在几个魅力阈值的大数据样本。阈值衰变拓扑为研究开放的粲衰变提供了特殊的机会。我们提出了一个选择最近的BESIII结果。支化分数和$D_{s}^{+}$衰变常数的测量使用的轻子衰变$μ^{+}ν$和$τ^{+}ν$。从在$D_{s}^{+}D_{s}^{-}$阈值处收集的$0.482 fb^{-1}$的数据样本中，我们测量$f_{Ds}=(241 \pm 16.3(stat.) \pm 6.6(sys.)) MeV$。BESIII最近发现了衰变$D_{s}^{+}\rightarrowτ^{+}ν$的初步证据，并且在$D^0\overline{D^0}$阈值处使用$2.81 fb^{-1}$数据的意义大于$4 σ$。使用相同的数据样本，分析衰减$D^0\rightarrow K^0_{S/L} π^0(π^0)$。测量支化分数，并使用$CP$本征态$K_{S/L}^0π^0$测量$D^0$混合参数$y_{CP} = (0.98 \pm 2.43)\%$。

英文摘要：

The study of mesons and baryons which contain at least one charm quark is referred to as open charm physics. It offers the possibility to study up-type quark transitions. Since the $c$ quark can not be treated in any mass limit, theoretical predictions are difficult and experimental input is crucial. BESIII collected large data samples of $e^{+}e^{-}$ collisions at several charm thresholds. The at-threshold decay topology offers special opportunities to study open charm decays. We present a selection of recent BESIII results. Branching fractions and the $D_{s}^{+}$ decay constant are measured using the leptonic decays to $μ^{+}ν$ and $τ^{+}ν$. From a data sample of $0.482 fb^{-1}$ collected at the $D_{s}^{+}D_{s}^{-}$ threshold we measure $f_{Ds}=(241 \pm 16.3(stat.) \pm 6.6(sys.)) MeV$. BESIII recently found preliminary evidence of the decay $D_{s}^{+}\rightarrowτ^{+}ν$ and with a significance larger than $4 σ$ using $2.81 fb^{-1}$ of data at the $D^0\overline{D^0}$ threshold. Using the same data sample the decay $D^0\rightarrow K^0_{S/L} π^0(π^0)$ is analysed. The branching fractions are measured and using the $CP$ eigenstates $K_{S/L}^0π^0$ the $D^0$ mixing parameter $y_{CP} = (0.98 \pm 2.43)\%$ is measured.

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。

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