Title: Measurement of the tau anomalous magnetic moment using Ultra-peripheral collisions with the ALICE detector in Run 3 Pb-Pb data Show Chinese title

Title: 使用ALICE探测器在Run 3 Pb-Pb数据中通过超外围碰撞测量tau子的异常磁矩

Abstract: The anomalous magnetic moment of the tau lepton ($a_{\tau}$) is a sensitive probe for the search for deviations from the Standard Model predictions and thus for new physics. This study investigates the feasibility of measuring $a_{\tau}$ using ultra-peripheral collisions (UPCs) at the LHC, where photon-photon interactions ($\gamma\gamma \to \tau^+ \tau^-$) produce tau lepton pairs. We focus on events recorded by the ALICE detector during Run 3 Pb-Pb data-taking. Events are selected in the decay channel where one tau decays into an electron and neutrinos, and the other decays into a charged pion, or three charged pions, and neutrinos. These samples are enhanced with decays into muons, which are inseparable in the ALICE detector. The clean environment of UPCs minimizes hadronic background, while the advanced particle identification capabilities of the ALICE Time Projection Chamber (TPC) and Time-of-Flight (TOF) systems allow for efficient separation of electrons, pions, and background particles. In this talk, prospects for measuring this process by ALICE in Run 3, which benefits from high statistics and improved systematics uncertainties, will be discussed. Results will provide tighter constraints on $a_{\tau}$, contributing to the broader effort to test the Standard Model's robustness and explore physics beyond it. Show Chinese abstract

Abstract: 缪子的反常磁矩（$a_{\tau}$）是寻找标准模型预测偏差以及新物理现象的敏感探针。 本研究探讨了在大型强子对撞机（LHC）上利用超外围碰撞（UPCs）测量$a_{\tau}$的可行性，其中光子-光子相互作用（$\gamma\gamma \to \tau^+ \tau^-$）产生缪子对。 我们关注的是在Run 3期间ALICE探测器记录的Pb-Pb数据中的事件。 事件选择在衰变通道中，其中一个缪子衰变为电子和中微子，另一个衰变为带电介子，或者三个带电介子和中微子。 这些样本通过衰变为μ子的事件进行了增强，这些事件在ALICE探测器中无法区分。 UPC的清洁环境减少了强子背景，而ALICE时间投影室（TPC）和飞行时间（TOF）系统的先进粒子识别能力允许有效地分离电子、介子和背景粒子。 在本次报告中，将讨论ALICE在Run 3中测量该过程的前景，这得益于高统计量和改进的系统不确定性。 结果将对$a_{\tau}$提供更严格的限制，有助于更广泛地测试标准模型的稳健性并探索其之外的物理现象。