Optimization and particle identification study of SPACAL calorimeter modules for LHCb ECAL Upgrade II

During electromagnetic calorimeter (ECAL) Upgrade II, the currently used Shashlik technology will need to be replaced to satisfy the future high luminosity requirements of the LHC. One of the promising candidates is the Spaghetti Calorimeter (SPACAL) technology. To assess its capabilities, the particle identification efficiencies of e −, µ +, π + and K+ were investigated for a wide range of particle energies, using energy parameters containing information about the transversal spread and the starting point of the electromagnetic showers in the detector. The results from the Boosted Decision Tree (BDT) method showed greatest separation between electrons and charged pions and demonstrated the benefit of longitudinal segmentation. Furthermore, the timing resolutions for the four types of particles in the potential SPACAL module configurations were obtained.