Searching for charged lepton flavour violation with the Mu3e experiment - Pixel Tracking Detector

Mu 3e第一阶段实验的主要目标是寻找违反伽马-> e e e衰变的带电轻子味，在90%的置信水平（CL）下，BR（伽马-> e e e）< 5 × 10−15，与现有的界限相比，相应地提高了200倍。需要高精度的跟踪来抑制μ子停止速率高达每秒10^8 μ子的大背景。电子的位置和动量将通过四层像素跟踪探测器（PTD）来测量，这是重建μ子衰变的关键。PTD项目包括Mu 3e像素跟踪探测器系统的建造、调试和校准、维护和操作，以及最终的数据分析。PTD项目提案还包括安装宇宙射线μ子触发器，该触发器将用于记录跟踪探测器对准的现场校准样本。

The main goal of the Mu3e Phase I experiment is the search for the charged lepton flavor violating decay gamma -> e e e with a sensitivity of BR(gamma -> e e e) < 5 × 10−15 at 90% confidence level (CL), corresponding to a factor 200 improvement compared to the existing bound. High precision tracking is required to suppress the large background at muon stopping rates of up to 10^8 muons per second. The position and momentum of electrons will be measured by means of a four layer pixel tracking detector (PTD) which is key for the reconstruction of the muon decays. The PTD project includes the construction of the Mu3e pixel tracking detector system, its commissioning and calibration, maintenance and operation, and eventually the data analysis. The PTD project proposal includes also the installation of the Cosmic Ray Muon Trigger which will be used to record in-situ calibration samples for trackingdetector alignment.