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

MU3E第一阶段实验的主要目标是寻找违反衰变伽马-gt；e的带电轻子味道，灵敏度为bR(伽马-gt；e e e)&lt；5×10−15，置信度为90%，与现有界限相比，相应地提高了200倍。需要高精度的跟踪来抑制高达每秒10^8微子的介子停止速率的大背景。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Muon衰变的关键。PTD项目包括Mu3e像素跟踪探测器系统的建设、调试和校准、维护和运行，最后是数据分析。PTD项目提案还包括安装宇宙线Muon触发器，该触发器将用于记录跟踪探测器对准的就地校准样品。

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.