The sensitivity of the dark photon search through invisible decay final states in low-background experiments relies sig-nificantly on the neutron and muon veto efficiencies,which depend on the amount of material used ...The sensitivity of the dark photon search through invisible decay final states in low-background experiments relies sig-nificantly on the neutron and muon veto efficiencies,which depend on the amount of material used and the design of the detector geometry.This paper presents the optimized design of the hadronic calorimeter(HCAL)used in the DarkSHINE experiment,which is studied using a GEANT4-based simulation framework.The geometry is optimized by comparing a traditional design with uniform absorbers to one that uses different thicknesses at different locations on the detector,which enhances the efficiency of vetoing low-energy neutrons at the sub-GeV level.The overall size and total amount of material used in the HCAL are optimized to be lower,owing to the load and budget requirements,whereas the overall performance is studied to satisfy the physical objectives.展开更多
This paper presents the design and optimization of a lutetium yttrium oxyorthosilicate(LYSO)crystal electromagnetic calorimeter(ECAL)for the DarkSHINE experiment,which aims to identify dark photons as potential mediat...This paper presents the design and optimization of a lutetium yttrium oxyorthosilicate(LYSO)crystal electromagnetic calorimeter(ECAL)for the DarkSHINE experiment,which aims to identify dark photons as potential mediators of dark forces.The ECAL design was evaluated through comprehensive simulations,focusing on optimizing dimensions,material selection,energy distribution,and energy resolution.The configuration consisted of 21×21×11 LYSO crystals,each measuring 2.5 cm×2.5 cm×4 cm,arranged in a staggered layout to enhance signal detection efficiency.A 4 GeV energy dynamic range was established to ensure accurate energy measurements without saturation,which is essential for background rejection and signal identification.A detailed digitization model was developed to simulate scintillation,silicon photomultiplier,and analog-to-digital converter behaviors,providing a realistic representation of the detector's performance.Additionally,the study assessed radiation damage in the ECAL region,emphasizing the importance of using radiation-resistant scintillators and silicon sensors.展开更多
Dark photons have been well motivated as strong candidates for dark force carriers and light dark matter in the sub-GeV mass range.Compared with collider experiments,fixed-target experiments provide a complementary ap...Dark photons have been well motivated as strong candidates for dark force carriers and light dark matter in the sub-GeV mass range.Compared with collider experiments,fixed-target experiments provide a complementary approach to searching for dark photons,particularly in the lower mass range.We have studied the physics potential of the electron-on-target experiment based on the Shanghai SHINE facility,which provides 10 MHz single electron beam at 8 GeV energy.This analysis focuses on dark photons being produced via electron and nucleon interaction and then decays to dark matter candidates,which escape detection as missing momentum in the detector.This experiment takes advantage of using missing momentum to enhance signal versus background separation power.In this study,signal samples as a function of dark photon mass and an inclusive background sample with 2.5 billion events are simulated with GEANT4.For better background estimates,major rare background processes have also been simulated.This paper presents the experiment and detector design,signal and background simulations,analysis strategy,and the prospective study of the experiment sensitivity.With 9×10^(14) electron-on-target events(about three years running),this experiment is expected to rule out most of the sensitive regions predicted by popular dark photon models.展开更多
基金supported by National Key R&D Program of China(Nos.2023YFA1606904 and 2023YFA1606900)National Natural Science Foundation of China(No.12150006)Shanghai Pilot Program for Basic Research-Shanghai Jiao Tong University(No.21TQ1400209).
文摘The sensitivity of the dark photon search through invisible decay final states in low-background experiments relies sig-nificantly on the neutron and muon veto efficiencies,which depend on the amount of material used and the design of the detector geometry.This paper presents the optimized design of the hadronic calorimeter(HCAL)used in the DarkSHINE experiment,which is studied using a GEANT4-based simulation framework.The geometry is optimized by comparing a traditional design with uniform absorbers to one that uses different thicknesses at different locations on the detector,which enhances the efficiency of vetoing low-energy neutrons at the sub-GeV level.The overall size and total amount of material used in the HCAL are optimized to be lower,owing to the load and budget requirements,whereas the overall performance is studied to satisfy the physical objectives.
基金supported by National Key R&D Program of China(Nos.2023YFA1606904 and 2023YFA1606900)National Natural Science Foundation of China(No.12150006)+1 种基金Shanghai Pilot Program for Basic Research-Shanghai Jiao Tong University(No.21TQ1400209)National Center for High-Level Talent Training in Mathematics,Physics,Chemistry,and Biology。
文摘This paper presents the design and optimization of a lutetium yttrium oxyorthosilicate(LYSO)crystal electromagnetic calorimeter(ECAL)for the DarkSHINE experiment,which aims to identify dark photons as potential mediators of dark forces.The ECAL design was evaluated through comprehensive simulations,focusing on optimizing dimensions,material selection,energy distribution,and energy resolution.The configuration consisted of 21×21×11 LYSO crystals,each measuring 2.5 cm×2.5 cm×4 cm,arranged in a staggered layout to enhance signal detection efficiency.A 4 GeV energy dynamic range was established to ensure accurate energy measurements without saturation,which is essential for background rejection and signal identification.A detailed digitization model was developed to simulate scintillation,silicon photomultiplier,and analog-to-digital converter behaviors,providing a realistic representation of the detector's performance.Additionally,the study assessed radiation damage in the ECAL region,emphasizing the importance of using radiation-resistant scintillators and silicon sensors.
基金supported by the National Natural Science Foundation of China(Grant No.12150006)Shanghai Pilot Program for Basic Research—Shanghai Jiao Tong University(Grant No.21TQ1400209)。
文摘Dark photons have been well motivated as strong candidates for dark force carriers and light dark matter in the sub-GeV mass range.Compared with collider experiments,fixed-target experiments provide a complementary approach to searching for dark photons,particularly in the lower mass range.We have studied the physics potential of the electron-on-target experiment based on the Shanghai SHINE facility,which provides 10 MHz single electron beam at 8 GeV energy.This analysis focuses on dark photons being produced via electron and nucleon interaction and then decays to dark matter candidates,which escape detection as missing momentum in the detector.This experiment takes advantage of using missing momentum to enhance signal versus background separation power.In this study,signal samples as a function of dark photon mass and an inclusive background sample with 2.5 billion events are simulated with GEANT4.For better background estimates,major rare background processes have also been simulated.This paper presents the experiment and detector design,signal and background simulations,analysis strategy,and the prospective study of the experiment sensitivity.With 9×10^(14) electron-on-target events(about three years running),this experiment is expected to rule out most of the sensitive regions predicted by popular dark photon models.
