Speaker
Description
Precision measurements of Higgs, W, and Z bosons at future lepton colliders demand jet energy reconstruction with unprecedented accuracy. The particle flow (PFA) approach has proven to be highly effective in achieving the required jet energy resolution. CyberPFA is a novel particle flow algorithm specifically designed for the crystal bar electromagnetic
calorimeter (ECAL) in the CEPC reference detector. This innovative calorimeter design combines superior intrinsic energy resolution with cost efficiency but introduces two critical reconstruction challenges: (1). Severe shower overlaps due to the material's large Molière radius ($R_M$) and large ratio of radiation length (X0) to nuclear interaction length ($\lambda_I$). (2) Ambbiguity problem caused by the perpendicular arrangement of crystal bars.
To overcome these challenges, CyberPFA introduces a breakthrough energy-core-based pattern recognition method, followed by an energy-splitting process to resolve overlapping showers. Additionally, multiple optimized pattern recognition techniques are implemented to address the ambiguity problem. Integrated with full detector simulation, CyberPFA achieves a 3.8% boson mass resolution for hadronic decays, surpassing the critical 4% threshold required for $W/Z$ separation.
These results demonstrate that: The long crystal bar ECAL is a viable and high-performance option for future colliders. CyberPFA’s energy-core-based reconstruction paradigm provides a novel and effective solution to imaging calorimeter reconstruction, specifically overcoming the critical challenges of shower overlaps in high-density environments. The algorithm’s innovative shower recognition approach is not only optimized for the current design but also adaptable to other imaging calorimeters, potentially enhancing their performance.
