The 2025 International Workshop on the High Energy Circular Electron Positron Collider

Precise jet energy reconstruction at the Circular Electron Positron Collider (CEPC) requires an advanced calorimetry system. A novel design for a particle-flow-oriented, high-granularity electromagnetic calorimeter (ECAL) has been proposed, featuring orthogonally layered crystal bars with silicon photomultiplier (SiPM) readout and a target energy resolution of $2\text{-}3\%/\sqrt{E...

The future Circular Electron-Positron Collider (CEPC) is a large-scale experimental facility, which aims to accurately measure the Higgs boson, electroweak physics and the top quark. For the detector system in CEPC, a highly granular crystal electromagnetic calorimeter is proposed to achieve an EM energy resolution of less than 3%. It is a homogenous structure with long crystal scintillator...

A highly granular Silicon-Tungsten ECAL is a way to obtain a high precision for a broad range of conditions and final states. An advanced model has been developed for the Linear Colliders. We will present the progress toward its adaptation for circular colliders: ASICs, timing, power, cooling, optimisation and final state reconstruction.

Particle flow algorithm (PFA) and dual-readout are advanced calorimeter technologies proposed for precise jet energy measurements at future colliders. PFA requires highly granular calorimeters for efficient particle separation and optimal energy reconstruction depending on particle type. Dual-readout improves hadronic energy resolution by incorporating both scintillation and Cherenkov...

The Future Circular Electron-Positron Collider (CEPC) demands advanced detector systems with excellent jet energy resolution. To address these requirements, a new high-granularity hadronic calorimeter design has been proposed. The major motivation is to significantly improve the hadronic energy resolution using high-density glass scintillator tiles to achieve a higher energy sampling fraction....

A technological prototype of high-granularity analog hadronic calorimeter (AHCAL) based on the plastic scintillator have been developed. The AHCAL prototype consists of a total of 12960 SiPM-on-Tile units in 40 longitudinal layers. Each layer is instrumented with plastic scintillator tiles as active material and a steel plate as absorber. In 2022 and 2023, the AHCAL prototype successfully...

A proposed highly-granular crystal ECAL for CEPC uses SiPMs to detect photon signals. Radiation-induced SiPM dark noise degrades calorimeter performance. A simulation study was performed to estimate the expected degradation in linearity of response and resolution due radiation damage to SiPMs. Simulations show dark noise causes up to 45% error in reconstructed energy for a 1 GeV electron...