The Circular Electron Positron Collider (CEPC) is a proposed Chinese electron positron collider for experimenting on the Higgs boson. If built, it would be the world's largest particle accelerator with a circumference of .
CEPC was proposed by the Chinese Academy of Sciences' Institute of High Energy Physics in 2012. A team of international physicists produced the design, and the technical design report was released in December 2023. In 2023 the projected cost was , including experiments. The project was not included in China's 15th Five-Year Plan (2026 to 2030). According to Wang Yifang, the CEPC will be resubmitted in 2030 only if there is no official approval for the Future Circular Collider.
Description CEPC is projected to have a maximum center-of-mass energy of 240 GeV. It will be located underground, and have two detectors. The electron-positron collisions will allow clearer observations than the proton-proton collisions of the Large Hadron Collider (LHC).
After 2040, the collider could be upgraded into the Super Proton–Proton Collider with collision energies seven times greater than the LHC.
Physics program The CEPC enables a wide physics program. As an electron-positron collider, it is suited to precision measurements, but also has strong discovery potential for new physics. Some possible physics goals include: Higgs measurements: Running slightly above the production threshold for ZH, the CEPC is a Higgs factory. Over the course of a ten-year run, it is planned to collect 5 ab−1 with two detectors, which corresponds to approximately one million produced Higgs Bosons. Workshop on Physics at the CEPC, August 10–12, 2015 One target is to be able to measure the ZH production cross-section to 0.5% accuracy. Other goals include the measurement of the Higgs Boson self coupling, and its coupling to other particles. When running at the Z peak, a precision measurement of the Z Boson mass and other properties, e.g. the Zbb̅ coupling, can be made. Workshop on Physics at the CEPC, August 10–12, 2015 Physics beyond the Standard Model: Workshop on Physics at the CEPC, August 10–12, 2015 Despite the lower center-of-mass energy compared to the LHC, the CEPC will be able to make discoveries or exclusions in certain scenarios where the LHC cannot. A prominent situation is when there is supersymmetry, but the masses of the superpartners are very close to each other (near-degenerate). In this case, when one SUSY particle decays into another plus a Standard Model particle, the SM particle will likely escape detection in a Hadron collider. In an e+e− collider, since the initial state is completely known, it is possible to detect such events by their missing energy (the energy carried away by SUSY particles and neutrinos).
See also
Large Electron–Positron Collider – LEP was the highest energy lepton collider ever built Compact Linear Collider – another post-LHC linear particle accelerator planned at CERN International Linear Collider – another post-LHC linear particle accelerator planned in Japan Future Circular Collider – a proposed 100 TeV circular collider at CERN
References
External links Record for CEPC on INSPIRE-HEP