北京谱仪III上通过粲奇异介子产生与衰变对部分奇特态的实验研究

Many states unlike conventional mesons, so called exotic states, were found at BESIII experiment and B-factories. For instance, Zc(3900)、Y(4260)、Ds0*(2317)、Ds1(2460) and so on, which could be molecular states, multi-quark states, hybrids and so on. The current results from experiments and the related theoretical investigation could not give certain conclusions. We propose a project based on the ee data between 3.8 and 4.6 GeV accumulated by BESIII experiment at BEPCII. The project includes the cross section spectra measurements of the processes ee to a charmed-strange-meson pair Ds(*)Ds(*), the observation of Ds0*(2317), Ds1(2460) by the singe Ds(*) tagging method, the measurements of Ds0*(2317), Ds1(2460) decays and so on. These experimental results would help better understanding the properties and nature of the charmonia, chamonium-like states and charmed-strange exotic states produced in this energy region. And they can also push the investigation and development of Quantum-Chromo-Dynamics at the low energy range.

BESIII实验以及B工厂实验上发现了很多与常规介子不同的所谓奇特态，比如Zc(3900)、Y(4260)、Ds0*(2317)、Ds1(2460)等，它们可能是分子态、多夸克态、混杂态等等，但目前的实验结果与相关理论研究尚不能给出明确的结论。本项目计划依托于北京正负电子对撞机BEPCII上的BESIII实验，利用3.8～4.6GeV能量区间的正负电子对撞数据，测量粲奇异介子对Ds(*)Ds(*)的产生截面谱，利用Ds(*)单标记技术寻找反冲信号Ds0*(2317)、Ds1(2460)，进而测量Ds0*(2317)、Ds1(2460)的衰变分支比等。这些实验研究结果将对该能区的粲偶素、类粲偶素奇特态、粲奇异介子奇特态的性质和结构有更深入的了解，促进量子色动力学在该能区的研究与发展。

BESIII及B工厂实验发现了诸多奇特态，如Zc(3900)、Y(4260)、Ds0*(2317)、Ds1(2460)等，它们可能是分子态、多夸克态、混合态等。目前的实验和理论研究尚无定论。以BEPCII对撞机上BESIII的ee对撞数据，我们利用Ds*单标记方法在4.6GeV首次观测到了ee->Ds*Ds0*(2317)，统计显著性5.8sigma，并首次测量分支比Br(Ds0(2317)->pi0Ds)为1.00^+0.00_-0.14+-0.14。该结果倾向于Ds0(2317)为分子态的解释。我们对CLEO-c的观测结果做了初态辐射和真空极化的修正得到3.970-4.260 GeV之间13个能量点ee到D0, D+、Ds介子的玻恩截面，并对结果的统计误差、系统误差做了合理估计。在BESIII实验上，我们同样利用Ds*单标记方法在4.23-4.6GeV能量区间观测了ee->Ds*Ds*过程，并通过对初态辐射、真空极化的迭代修正以更好的精度获得了其玻恩截面的测量结果。这些实验结果有助于理解该能区粲偶素、类粲偶素、粲奇异介子（奇特态）的性质和本质，也推动了低能区量子色动力学理论研究的发展。