论文标题
观察$ \ sqrt {s_ \ mathrm {nn}} $ = 5.02 TEV的$ \ sqrt {s_ \ mathrm {s_ \ mathrm {s_ \ sqrt {
Observation of $τ$ lepton pair production in ultraperipheral lead-lead collisions at $\sqrt{s_\mathrm{NN}}$ = 5.02 TeV
论文作者
论文摘要
我们介绍了超递铅铅撞击$τ$ Lepton对的光子光子产生的观察。该测量基于数据样本，其集成光度为404 $ $ $ b $ b $^{ - 1} $由CMS实验收集的核子核苷中心能量为5.02 TEV。 $γγ$ $ \至$τ^+τ^ - $ $进程是针对带有MUON的$ττ$事件观察到的，最终状态下有三个带电的Hadron。测量的基准横截面为$σ（γγ$ $ \至$ $τ^+τ^ - ）$ = 4.8 $ \ pm $ 0.6（stat）$ \ pm $ 0.5（syst）$ $ $ b，与前级QED预测一致。使用$σ（γγ$ $ \至$ $ $ $τ^+τ^ - ）$，我们估计$a_τ$ = 0.001 $^{+0.055} $a_τ$ = 0.001 $ = 0.055} _ { - 0.089} $的$τ$ Lepton的模型依赖性值。
We present an observation of photon-photon production of $τ$ lepton pairs in ultraperipheral lead-lead collisions. The measurement is based on a data sample with an integrated luminosity of 404 $μ$b$^{-1}$ collected by the CMS experiment at a nucleon-nucleon center-of-mass energy of 5.02 TeV. The $γγ$ $\to$ $τ^+τ^-$ process is observed for $ττ$ events with a muon and three charged hadrons in the final state. The measured fiducial cross section is $σ(γγ$ $\to$ $τ^+τ^-)$ = 4.8 $\pm$ 0.6 (stat) $\pm$ 0.5 (syst) $μ$b, in agreement with leading-order QED predictions. Using $σ(γγ$ $\to$ $τ^+τ^-)$, we estimate a model-dependent value of the anomalous magnetic moment of the $τ$ lepton of $a_τ$ = 0.001 $^{+0.055}_{-0.089}$.
