Speaker
Description
Precision measurements of Higgs, W, and Z bosons at future lepton colliders demand jet energy reconstruction with unprecedented accuracy. The particle flow approach has proven to be an effective method for achieving the required jet energy resolution. We present CyberPFA, a particle flow algorithm specifically optimized for the particle-flow-oriented crystal bar electromagnetic calorimeter (ECAL) in the CEPC reference detector. This innovative calorimeter design combines excellent intrinsic energy resolution with cost efficiency, but introduces two major reconstruction challenges: (1) increased shower overlaps due to the material's large $R_M$ and $X_0/\lambda_I$, and (2) ambiguity problem caused by the perpendicular arrangement of crystal bars.
The issue of shower overlap has been solved by an energy-core-based pattern recognition method followed by an energy splitting process. The ambiguity problem has been addressed through the implementation of multiple optimized pattern recognition approaches. Integrated with the full detector simulation, CyberPFA achieves a 3.8% boson mass resolution for hadronic decays, exceeding the critical 4% threshold required for W/Z separation.
These results not only validate the long crystal bar ECAL as a viable design choice for future colliders but also highlight the exceptional performance of CyberPFA and the advanced nature of its energy-core-based reconstruction paradigm. The algorithm’s innovative approach to shower recognition is not only effective for the current design but can also be extended to other imaging calorimeter reconstruction algorithms, significantly improving their performance.
