BESIII电磁量能器位置重建及其修正

摘要

In the paper , we study position reconstruction and its correction for the BESIII Electromagnetic Calo -rimeter (EMC).For Monte-Carlo (MC) data, we obtain the position correction parameters in polar angle and azimuthal angle by using MC single electron and photon samples respectively .The corrections of polar angle and azimuthal angle take into account the dependence of energy and polar angle .For real data , we correct its small difference from MC data by using Bhabha events .Finally, we give the performance of the position reconstruc-tion by Bhabha events and digamma events , MC data and real data position resolution are basically identical . The results show that electron position resolution at 1 GeV is about 5.6mm which reaches its designed goal .%介绍了BESIII电磁量能器（ EMC）位置重建及其修正的研究工作。利用蒙特卡罗模拟（ MC）单电子和单光子分别对θ向和φ向进行修正，修正参数考虑了能量和位置依赖；对于真实数据，θ向位置修正量与MC修正量有微小差异，在MC修正的基础上，利用Bhabha数据确定真实数据的二次修正参数。利用Bhabha事例和双光子事例检验EMC位置重建性能，MC模拟与真实数据位置分辨基本一致，动量为1 GeV的电子在θ向位置分辨达到5．6 mm，达到了BESIII EMC的设计指标。