观测 D^{0}→a_{0}(980)^{-}e^{+}ν_{e} 的半轻子衰变和 D^{+}→a_{0}(980)^{0}e^{+}ν_{e} 的证据。

Observation of the Semileptonic Decay D^{0}→a_{0}(980)^{-}e^{+}ν_{e} and Evidence for D^{+}→a_{0}(980)^{0}e^{+}ν_{e}.

机构信息

Institute of High Energy Physics, Beijing 100049, People's Republic of China.

G.I. Budker Institute of Nuclear Physics SB RAS (BINP), Novosibirsk 630090, Russia.

出版信息

Phys Rev Lett. 2018 Aug 24;121(8):081802. doi: 10.1103/PhysRevLett.121.081802.

DOI:10.1103/PhysRevLett.121.081802

PMID:30192571

Abstract

Using an e^{+}e^{-} collision data sample of 2.93 fb^{-1} collected at a center-of-mass energy of 3.773 GeV by the BESIII detector at BEPCII, we report the observation of D^{0}→a_{0}(980)^{-}e^{+}ν_{e} and evidence for D^{+}→a_{0}(980)^{0}e^{+}ν_{e} with significances of 6.4σ and 2.9σ, respectively. The absolute branching fractions are determined to be B(D^{0}→a_{0}(980)^{-}e^{+}ν_{e})×B(a_{0}(980)^{-}→ηπ^{-})=[1.33_{-0.29}^{+0.33}(stat)±0.09(syst)]×10^{-4} and B(D^{+}→a_{0}(980)^{0}e^{+}ν_{e})×B(a_{0}(980)^{0}→ηπ^{0})=[1.66_{-0.66}^{+0.81}(stat)±0.11(syst)]×10^{-4}. This is the first time the a_{0}(980) meson has been measured in a D^{0} semileptonic decay, which would open one more interesting page in the investigation of the nature of the puzzling a_{0}(980) states.

摘要

使用北京正负电子对撞机上的 BESIII 探测器在质心能量为 3.773 GeV 下收集的 2.93 fb^{-1}的 e^{+}e^{-}碰撞数据样本，我们报告了 D^{0}→a_{0}(980)^{-}e^{+}ν_{e}和 D^{+}→a_{0}(980)^{0}e^{+}ν_{e}的观测结果，其显著性分别为 6.4σ和 2.9σ。绝对分支比分别被确定为 B(D^{0}→a_{0}(980)^{-}e^{+}ν_{e})×B(a_{0}(980)^{-}→ηπ^{-})=[1.33_{-0.29}^{+0.33}(stat)±0.09(syst)]×10^{-4}和 B(D^{+}→a_{0}(980)^{0}e^{+}ν_{e})×B(a_{0}(980)^{0}→ηπ^{0})=[1.66_{-0.66}^{+0.81}(stat)±0.11(syst)]×10^{-4}。这是首次在 D^{0}半轻子衰变中测量到 a_{0}(980)介子，这将为研究令人困惑的 a_{0}(980)状态的本质打开更多有趣的一页。