北京谱仪III上奇异介子和奇异夸克偶素的实验研究

The project leader has much experience in the experimental particle physics. At BESII experiment, I made substantial contributions to search for the new forms of particles, in particular in the discovery of X(1835) particle. I am now is focusing on the study of light hadron spectroscopy at BESIII experiment. Many significant progresses on the search for new light hadrons and η/η′ physics were achieved in recent years...The study of strange meson and strangeonium spectroscopy is of particular interest since the srange quark a bridge between the light u, d quarks and the heavy c, b quarks. However, there are still many unseen states predicted by the quark model for which the experimental situation is not well understood. The BESIII experiment has collected the world’s largest samples of J/ψ,ψ(2S) and ψ(3770) events and will continue to accumulate high quality, large integrated luminosity in the τ-charm energy egion. These data, combined with the excellent performance of the BESIII detector, will offer unprecedented opportunities to explore the strange meson and strangeonium spectroscopy...An overview of the strange meson and strangeonium spectroscopy and the experiment status is presented. Based on the poor experimental situation, we propose to perform an extensive study on the strange mesons, strangeonium states via charmonium decays at the BESIII experiment. In addition to their production rate and decay dynamics, we also propose to search for new strange hadrons, e.g., strangeonium-like states, and measure their mass, width and spin-parity to complete the strange hadron spectroscopy, which not only help to test the theoretical models, also to deepen our understanding on the structure of light hadrons.

申请人长期从事高能物理实验,研究曾参加北京谱仪II实验和德国ZEUS实验。在BESII实验发现X(1835)新粒子过程中做出了突出贡献，并获得国家自然科学二等奖；目前主要从事轻强子谱及新强子态寻找等研究工作，并取得许多重要成果。. 夸克模型预言存在许多奇异介子和奇异夸克偶素实验上尚未观测到，实验数据又十分匮乏，所以尽快开展对奇异介子和奇异夸克偶子的系统研究具有重要科学意义。详细调研表明北京谱仪III实验在开展该领域研究的国际竞争中具有明显优势。基于北京谱仪III实验所采集的高统计量粲偶素衰变数据，本项目申请开展奇异介子、奇异夸克偶素的系统研究，同时寻找类奇异夸克偶素等新物理现象，深入了解它们的产生及衰变机制，测量它们的质量宽度等性质，完善奇异强子谱，检验各种理论模型，进而加深对夸克模型及强子结构的认识，促进低能区量子色动力学理论的发展。

夸克模型预言存在许多奇异介子和奇异夸克偶素实验上尚未观测到，实验数据又十分匮乏，所以尽快开展对奇异介子和奇异夸克偶子的系统研究具有重要科学意义。详细调研表明北京 谱仪III实验在开展该领域研究的国际竞争中具有明显优势。基于北京谱仪III实验所采集的高统计量粲偶素衰变数据，本项目申请开展奇异介子、奇异夸克偶素的系统研究，同时寻找类奇异夸克偶素等新物理现象，深入了解它们的产生及衰变机制，测量它们的质量宽度等性质，完善奇异强子谱，检验各种理论模型，进而加深对夸克模型及强子结构的认识，促进低能区量子色动力学理论的发展。. 项目利用北京谱仪III所采集的高质量的J/ψ和ψ（2S）数据，针对轻介子衰变的开展了相关实验研究，开发相应的事例产生子，并取得一系列创新研究成果，受到广泛关注。项目执行期间共在 Phys. Rev. Lett.、 Phys. Rev.D等杂志上发表39篇文章。主要物理成果包括:（1）包括首次观测到a0(980)-f0(980)混合;(2)首次观测到奇异夸克偶素X（1750）；（3）首次观测到奇特态eta1(1855);(3)首次观测到X（2370）新衰变模式; (4) 首次观测到etaprime的一系列新衰变模式等。. 这一系列研究成果不仅检验了低能区的理论模型，还丰富了轻介子谱的内容，为理解介子的内部结构提供了重要实验数据，进而加深对轻强子谱的内部结构的理解，推动理论上对强子领域的研究进展。