LHCb实验观测到的可能的四夸克态■（英文）

作者：赵光达^*; 朱世琳^*

来源：Science Bulletin, 2020, 65(23): 1952-1953.

<正>The molecular positronium (sometimes also denoted as di-positronium) was the multi-electron bound state composed of e+e-e+e-,where the electromagnetic interaction is the underlying driving force.Although its existence was predicted as early as in1947[1],it remained elusive until it was produced experimentally in 2007[2].One may wonder whether there exists the analogue of the di-positronium in Quantum Chromodynamics,which is the tetraquark state with the flavor configurations ■.Very recently,the LHCb Collaboration observed distinct structures with the ■(two charm quarks and two anti-charm quarks) in the J/ψ w-pair mass spectrum[3].They reported a broad structure ranging from6.2 to 6.8 GeV and a narrow structure at around 6.9 GeV with a global significance of more than 5r.Let’s denote it as T4c.

• 单位
  核物理与核技术国家重点实验室; 北京大学