Nara Women's University, Nara 630-8506.
Phys Rev Lett. 2013 Jul 19;111(3):032001. doi: 10.1103/PhysRevLett.111.032001. Epub 2013 Jul 16.
We report measurements of B→χ(c1)γK and χ(c2)γK decays using 772×10(6) BB[over ¯] events collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. Evidence of a new resonance in the χ(c1)γ final state is found with a statistical significance of 3.8σ. This state has a mass of 3823.1±1.8(stat)±0.7(syst) MeV/c(2), a value that is consistent with theoretical expectations for the previously unseen 1(3)D(2) cc[over ¯] meson. We find no other narrow resonance and set upper limits on the branching fractions of the X(3872)→χ(c1)γ and χ(c2)γ decays.
我们报道了 Belle 探测器在 KEKB 正负电子对撞机上利用 772×10(6)BB[over ¯]事件，对 B→χ(c1)γK 和 χ(c2)γK 衰变的测量结果。在 χ(c1)γ 末态中发现了一个新的共振，其统计显著性为 3.8σ。这个状态的质量为 3823.1±1.8(stat)±0.7(syst)MeV/c(2)，与之前未观测到的 1(3)D(2)cc[over ¯]介子的理论预期值一致。我们没有发现其他窄共振，并对 X(3872)→χ(c1)γ 和 χ(c2)γ 衰变的分支比设定了上限。
