Project overview
The Circular Electron Positron Collider (CEPC) is a large international scientific facility proposed by the Chinese particle-physics community in 2012 to explore the electroweak, Higgs and flavour physics programme. To be hosted in China in a circular underground tunnel of approximately 100 km in circumference, the CEPC is a double-ring collider with electron and positron beams circulating in opposite directions in separate beam pipes, and detectors installed at two interaction points (IPs).
The CEPC will operate in three different modes: H (e+e− → ZH), Z (e+e− → Z) and W (e+e− → W+W−). The centre-of-mass energies are 240 GeV, 91 GeV and 160 GeV, with luminosities of 5 × 1034, 116 × 1034 and 16 × 1034 cm−2s−1, respectively.
The primary physics goal is to use the CEPC as a Higgs factory. A tentative “10-2-1” operation plan foresees 10 years as a Higgs factory producing about 2.6 million Higgs bosons, followed by 2 years as a Super Z factory producing about 2.5 trillion Z bosons, and 1 year as a W factory producing about 130 million W bosons. The enormous number of bottom quarks, charm quarks and τ-leptons produced in Z decays also makes the CEPC an effective B-factory and τ-charm factory. Together, these modes provide an unmatched opportunity for precision measurements and searches for physics beyond the Standard Model.
The CEPC collider will be an advanced factory of Higgs, Z and W bosons and the top quark, as well as of QCD events and many interesting hadrons. It will be used to discover new physics and unknowns.
Timeline and progress
The concept of a timeline and progress with the CEPC project is:
- The first stage was to complete a Preliminary Conceptual Design Report (Pre-CDR) in 2015 and a Conceptual Design Report (CDR) in 2018. With the publication of these reports, these goals have been achieved.
- The next stage, from 2018 to 2025, was for R&D and the completion of a Technical Design Report (TDR). These goals have been achieved.
- The next stage, from 2024 to 2027, is for the Engineering Design Report (EDR).
- The team is working towards the final approval in the government’s 16th Five-Year Plan.