Modeling scintillation photon transport and reconstruction algorithms for the time-of-flight detector in the T2K neutrino experiment

The T2K ND280 upgrade aims to reduce the systematic uncertainty of the CP-violating phase, δ CP, to reject non-CP violation hypothesis at 3σ confidence level. A crucial component of the ND280 upgrade, alongside the Super Fine Grained Detector (SuperFGD) and two High-Angle Time Projection Chambers (TPCs), is the Time-of-Flight (ToF) detector, which significantly enhances background rejection and particle identification capabilities. The ToF detector features six modules in a cube configuration, each with 20 plastic scintillator bars measuring 220×12×1 cm3 and is equipped with Silicon Photomultiplier (MPPC) arrays at both ends to capture scintillation light. This letter outlines the modelling of the detector response and the signal reconstruction process.