The Circular Electron Positron Collider (CEPC) is a proposed Chinese
electron positron collider for experimenting on the
Higgs boson
The Higgs boson, sometimes called the Higgs particle, is an elementary particle in the Standard Model of particle physics produced by the quantum excitation of the Higgs field,
one of the fields in particle physics theory. In the St ...
. It would be the world's largest
particle accelerator
A particle accelerator is a machine that uses electromagnetic fields to propel electric charge, charged particles to very high speeds and energies, and to contain them in well-defined particle beam, beams.
Large accelerators are used for fun ...
with a circumference of .
CEPC was proposed by the
Chinese Academy of Sciences
The Chinese Academy of Sciences (CAS); ), known by Academia Sinica in English until the 1980s, is the national academy of the People's Republic of China for natural sciences. It has historical origins in the Academia Sinica during the Repub ...
' Institute of High Energy Physics in 2012.
Projections in 2023 were for a proposal to be submitted to the government in 2025, and construction taking place from 2027 to 2035; the projected cost was , including experiments.
The design was produced by a team of international physicists.
The technical design report was released in December 2023.
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
The Large Hadron Collider (LHC) is the world's largest and highest-energy particle collider. It was built by the European Organization for Nuclear Research (CERN) between 1998 and 2008 in collaboration with over 10,000 scientists and hundr ...
(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
A Higgs Factory is a particle accelerator designed to produce Higgs Bosons at a very high rate, allowing precision studies of this particle. A Higgs factory was identified as the highest future priority of particle physics in the 2020 European St ...
. 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. 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.
*
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
The Large Electron–Positron Collider (LEP) was one of the largest particle accelerators ever constructed. It was built at CERN, a multi-national centre for research in nuclear and particle physics near Geneva, Switzerland.
LEP collided elec ...
- LEP was the highest energy lepton collider ever built
*
Compact Linear Collider
The Compact Linear Collider (CLIC) is a concept for a future linear particle accelerator that aims to explore the next energy frontier. CLIC would collide electrons with positrons and is currently the only mature option for a multi-TeV linear colli ...
– another post-LHC linear particle accelerator planned at
CERN
*
International Linear Collider
The International Linear Collider (ILC) is a proposed linear particle accelerator. It is planned to have a collision energy of 500 GeV initially, with the possibility for a later upgrade to 1000 GeV (1 TeV). Although early proposed ...
– another post-LHC linear particle accelerator planned in Japan
*
Future Circular Collider
The Future Circular Collider (FCC) is a proposed particle accelerator with an energy significantly above that of previous circular colliders, such as the Super Proton Synchrotron, the Tevatron, and the Large Hadron Collider (LHC). The FCC proje ...
– a proposed 100 TeV circular collider at CERN
References
{{reflist
External links
* Record fo
CEPCon
INSPIRE-HEP INSPIRE-HEP is an open access digital library for the field of high energy physics (HEP). It is the successor of the Stanford Physics Information Retrieval System (SPIRES) database, the main literature database for high energy physics since the 1970 ...
Particle physics facilities
Particle experiments
Science and technology in China
Proposed particle accelerators