Yerevan Physics Institute, Yerevan, Armenia.
Phys Rev Lett. 2011 May 27;106(21):212301. doi: 10.1103/PhysRevLett.106.212301. Epub 2011 May 24.
A search for Z bosons in the μ(+)μ(-) decay channel has been performed in PbPb collisions at √S(NN)=2.76 TeV with the CMS detector at the LHC, in a 7.2 μb(-1) data sample. The number of opposite-sign muon pairs observed in the 60-120 GeV/c(2) invariant mass range is 39, corresponding to a yield per unit of rapidity (y) and per minimum bias event of [33.8±5.5(stat)±4.4(syst)]×10(-8), in the |y|<2.0 range. Rapidity, transverse momentum, and centrality dependencies are also measured. The results agree with next-to-leading order QCD calculations, scaled by the number of incoherent nucleon-nucleon collisions.
使用 CMS 探测器在 LHC 上对质心能量为 √S(NN)=2.76 TeV 的 PbPb 碰撞中的 μ(+)μ(-) 衰变道进行了 Z 玻色子的搜索，数据样本量为 7.2 μb(-1)。在 60-120 GeV/c(2)不变质量范围内观测到的相反符号μ子对的数量为 39，对应的单位快度 (y) 和每单位最小偏倚事件的产额为 [33.8±5.5(stat)±4.4(syst)]×10(-8)，在 |y|<2.0 范围内。还测量了快度、横动量和中心度依赖性。结果与通过非相干核子-核子碰撞数缩放的次领头阶 QCD 计算相符。
