The universe is thought to be filled with not only Standard Model (SM) matters but also dark matters. Dark matter is thought to play a major role in its construction. However, the identity of dark matter is as yet unknown, with various search methods from astrophysical observartion to particle collider experiments. Because of the cross-section that is a thousand times smaller than SM particles, dark matter research requires a large amount of data processing. Therefore, optimization and parallelization in High Performance Computing is required. Dark matter in hypothetical hidden sector is though to be connected to dark photons which carries forces similar to photons in electromagnetism. In the recent analysis, it was studied using the decays of a dark photon at collider experiments. Based on this, we studies double dark photon decays at lepton colliders. The signal channels are e+e– → AʹAʹ and e+e– → AʹAʹγ where dark photon Aʹ decays dimuon. These signal channels are based on the theory that dark photons only decay into heavily charged leptons, which can explain the muon magnetic momentum anomaly. We scanned the cross-section according to the dark photon mass in experiments. MadGraph5 was used to generate events based on a simplified model. Additionally, to get the maximum expected number of events for the double dark photon channel, the detector efficiency for several center of mass (CM) energy were studied using Delphes and MadAnalysis5 for performance comparison. The results of this study will contribute to the search for double dark photon channels at lepton colliders.

1. INTRODUCTION
2. METHODS
3. THEORY
4. DOUBLE DARK PHOTON GENERATION
    4.1. Cross-Section of Background Processes, e+e– →μ+μ–μ+μ–(γ)
    4.2 Cross-Section of Signal Processes , e+e– → AʹAʹ(γ)
5. RESULTS
6. CONCLUSION
ACKNOWLEDGMENTS
REFERENCES

• Kihong Park(University of Science and Technology, Daejeon 34113, Korea, Korea Institute of Science and Technology Information, Daejeon 34141, Korea)
• Kyungho Kim(Korea Institute of Science and Technology Information, Daejeon 34141, Korea)
• Kihyeon Cho(University of Science and Technology, Daejeon 34113, Korea, Korea Institute of Science and Technology Information, Daejeon 34141, Korea) Corresponding author