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.
Phys Rev Lett. 2014 Apr 4;112(13):132001. doi: 10.1103/PhysRevLett.112.132001. Epub 2014 Apr 2.
We study the process e+ e- →(D* D*)± π∓ at a center-of-mass energy of 4.26 GeV using a 827 pb(-1) data sample obtained with the BESIII detector at the Beijing Electron Positron Collider. Based on a partial reconstruction technique, the Born cross section is measured to be (137±9±15) pb. We observe a structure near the (D* D*)± threshold in the π∓ recoil mass spectrum, which we denote as the Zc±(4025). The measured mass and width of the structure are (4026.3±2.6±3.7) MeV/c2 and (24.8±5.6±7.7) MeV, respectively. Its production ratio σ(e+ e- → Zc±(4025)π∓ → (D* D*)± π∓)/σ(e+ e- → (D* D*)± π∓) is determined to be 0.65±0.09±0.06. The first uncertainties are statistical and the second are systematic.
我们使用北京正负电子对撞机上的 BESIII 探测器在 4.26GeV 的质心能量下研究了 e+ e- →(D* D*)± π∓的过程。基于部分重建技术，测量到的 Born 截面为 (137±9±15) pb。我们在 π∓反冲质量谱中观察到 (D* D*)± 阈附近的一个结构，我们将其表示为 Zc±(4025)。该结构的测量质量和宽度分别为 (4026.3±2.6±3.7) MeV/c2 和 (24.8±5.6±7.7) MeV。其产生比 σ(e+ e- → Zc±(4025)π∓ → (D* D*)± π∓)/σ(e+ e- → (D* D*)± π∓) 被确定为 0.65±0.09±0.06。第一个不确定度是统计不确定度，第二个是系统不确定度。
