Hybrid Electromagnetic Calorimeter Module: Enhanced Performance through Integration of Silicon Pixel Layer into Scintillator Design

Abstract: This study constructs a hybrid module with a multi-material collaborative detection architecture by integrating silicon pixel layers into the longitudinally segmented scintillating fiber sampling calorimeter module and optimizes the placement of the silicon layers. The module utilizes the pre-shower characteristics of the front-end scintillator units to ensure sufficient energy deposition in the silicon pixel layers, thereby maintaining its high-precision detection capability. A dedicated simulation framework combining Geant4 modeling for the scintillator section and a parameterized approach for the silicon pixel layer is employed for module verification and performance study. The hybrid module demonstrates overall performance enhancement. The maximum achievable improvements are 56\% for position resolution and 26\% for time resolution, respectively. These advancements also lead to significant increase of physics sensitivity, especially for physics channels with low-energy photons, for instance, a 16\% boost in signal significance for $D^{*0}$ from the $B^-\rightarrow D^{*0}(\rightarrow D^0 \gamma)\pi^-$ decay