BESIII实验上e+ e- ->D Dbar (π) π产生的研究

粲夸克偶素谱的研究一直是强子物理前沿的热点问题。在粲介子对产生质量阈值之上， ψ(4415)是实验上已经发现的一个高激发态的粲夸克偶素态。目前对它的性质了解得还不够充分，不同理论的解释也存在争议，而ψ(4415)的实验研究也很有限。本项目旨在深入理解高激发态的粲夸克偶素ψ(4415)相关物理的研究。基于BESIII实验上质心系能量4 GeV以上的高统计量数据，本项目通过对e+e- ->DD_1 ->DDbarππ和e+e- ->DD_2->DDbarπ过程的研究，将提升我们对矢量粲夸克偶素介子ψ(4415)的性质及其强衰变的了解。同时，我们还将在e+e- ->D+D-π+π-过程中寻找可能的D-Dbar束缚态。

The study of charmonium spectrum is a hot topic in the frontier of hadron physics. Above DDbar mass threshold, ψ(4415) is one of higher excited charmonia, which is discovered by the experiment of e+e- annihilation. At present, its property is not well understood. There are some contradictions between different theoretical explanations for ψ(4415), and the evidence of the experiment is limited for the study of ψ(4415). In the project, we will focus on a deep understanding of the high excited charmonium ψ(4415) related Physics. Based on the BESIII data samples with high luminosity around 4.4 GeV, the processes e+e- ->DD_1 ->DDbarππ and e+e- ->DD_2->DDbarπ will be studied to improve our knowledge on the property of ψ(4415) and the hadronic decays of the vector charmonium. Meanwhile, we will search the possible bound states of D-Dbar system near D-Dbar threshold in the process e+e- ->D+D-π+π-.