Improvements on the particle identification with dead cell and side leakage corrections for the electromagnetic calorimeter of the Alpha Magnetic Spectrometer  

作　　者：Shao-Wen Zhang Zu-Hao Li Xue-Qiang Wang Cheng Zhang Zhi-Cheng Tang Suzan Basegmez du Pree Fei Zhao Ze-Tong Sun Guo-Ming Chen He-Sheng Chen 

机构地区：[1]Key Laboratory of Particle Astrophysics,Institute of High Energy Physics,Chinese Academy of Science,Beijing 10049,China [2]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Radiation Detection Technology and Methods》2018年第2期14-18,共5页辐射探测技术与方法（英文）

摘　　要：Background The electromagnetic calorimeter(ECAL)of the Alpha Magnetic Spectrometer(AMS-02)measures the energy of electrons/positrons and separates them from protons.Currently,there are five dead cells in the ECAL which affect the reconstructed energy of particles.The particle identification power of the ECAL decreases when particles pass through these dead cells or close to the ECAL border.Purpose To improve the ECAL particle identification for particles pass through these dead cells or close to the ECAL border.Methods An improved ECAL particle identification estimator using the electromagnetic shower shape is developed with dead cell and side leakage corrections.Results For events passing through dead cells,with this new estimator,the proton rejection power is improved by a factor of 2.2 and positron purity is improved from 31 to 50%in the energy range of 500–800 GeV.Conclusion The new estimator works well for event passing through dead cells or close to the ECAL border.

关 键 词：Electron/proton separation Electromagnetic calorimeter(ECAL) Boosted Decision Trees(BDT) Dead cell correction Side leakage correction 

分 类 号：O57[理学—粒子物理与原子核物理]