China plans colliders that would dwarf CERN's LHC.
For the previous few decades, Europe and the United States have led the way when it comes to high-energy particle colliders. But a proposal by China that is quietly gathering momentum has raised the possibility that the country could soon position itself at the forefront of particle physics with huge new projects.
Scientists at the Institute of High Energy Physics (IHEP) in Beijing, working with international collaborators, are planning to build a ‘Higgs factory’ by 2028, a 52-kilometre underground ring that would smash together electrons and positrons. Collisions of these fundamental particles would allow the Higgs boson to be studied with greater precision than at the much smaller Large Hadron Collider (LHC) at CERN, Europe’s particle-physics laboratory near Geneva, Switzerland.
Physicists say that the proposed US$3-billion machine is within technological grasp and is considered conservative in scope and cost. But China hopes that it would also be a stepping stone to a next-generation collider, a super proton–proton collider, in the same tunnel. European and US teams have both shown interest in building their own super collider, but the huge amount of research needed before such a machine could be built means that the earliest date either can aim for is 2035.
China would like to build its electron–positron collider in the meantime, unaided by international funding if needs be, and follow it up as fast as technologically possible with the super proton collider. Because only one super collider is likely to be built, China’s momentum puts it firmly in the driving seat. Speaking this month at the International Conference on High Energy Physics in Valencia, Spain, IHEP director Yifang Wang said that, to secure government support, China wanted to work towards a more immediate goal than a super collider by 2035. “You can’t just talk about a project which is 20 years from now,” he said.