标题：Observation of a charged (DD∗)± Mass Peak in e+e-→ πdD ∗ at √s=4.26 GeV
作者：Ablikim, M. ;Achasov, M.N. ;Albayrak, O. ;Ambrose, D.J. ;An, F.F. ;An, Q. ;Bai, J.Z. ;Baldini Ferroli, R. ;Ban, Y. ;Becker, J. ;Bennett, J.V. ;Bertani 更多 作者机构：[Lou, X.C. ] University of Texas at Dallas, Richardson; TX; 75083, United States;[Achasov, M.N. ] Novosibirsk State University, Novosibirsk; 630090, R 更多
来源：Physical Review Letters
摘要：We report on a study of the process e+e-→π±(DD¯*) - at s=4.26 GeV using a 525 pb-1 data sample collected with the BESIII detector at the BEPCII storage ring. A distinct charged structure is observed in the (DD¯*)- invariant mass distribution. When fitted to a mass-dependent-width Breit-Wigner line shape, the pole mass and width are determined to be Mpole=(3883.9±1.5(stat)±4.2(syst)) MeV/c2 and Γpole=(24.8±3.3(stat)±11.0(syst)) MeV. The mass and width of the structure, which we refer to as Zc(3885), are 2σ and 1σ, respectively, below those of the Zc(3900)→π±J/ψ peak observed by BESIII and Belle in π+π-J/ψ final states produced at the same center-of-mass energy. The angular distribution of the πZc(3885) system favors a JP=1+ quantum number assignment for the structure and disfavors 1- or 0-. The Born cross section times the DD¯* branching fraction of the Zc(3885) is measured to be σ(e+e-→π±Zc(3885)-) ×B(Zc(3885)- →(DD¯*)-)=(83.5±6.6(stat)±22. 0(syst)) pb. Assuming the Zc(3885)→DD¯* signal reported here and the Zc(3900)→πJ/ψ signal are from the same source, the partial width ratio (Γ(Zc(3885)→DD¯*)/Γ(Zc(3900)→πJ/ ψ))=6.2±1.1(stat)±2.7(syst) is determined.
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