Sep 05, 2016

China’s ambitious plans to build its own particle collider will not be worth it, Nobel prize-winning physicist Chen-Ning Yang argued in a commentary published Sunday.

Construction on the Circular Electron Positron Collider (CEPC) is slated to start in 2021. Upon its completion in six years, it would be the world’s largest particle accelerator. With a circumference of at least 50 kilometers — its exact size has not yet been decided — it would be far larger than the current record-holding machine, the Large Hadron Collider (LHC) at the European Organization for Nuclear Research, better known as CERN, beneath the border shared by France and Switzerland.

Such massive colliders allow scientists to study the universe’s smallest particles. The LHC in 2012 proved the existence of the Higgs boson, an elusive particle that had long puzzled scientists.

An even larger accelerator, such as the one planned by China, could collide particles at even higher energies and make discoveries that are impossible with existing colliders. However, some people in the scientific community, including Yang, do not agree with the project.

In an article published on WeChat public account The Intellectual, the Chinese-born American physicist argues that the costs of building the super collider are too high and not worth it considering China’s current situation. Yang called the high cost of the collider “a bottomless pit,” comparing it to the Superconducting Super Collider project, which cost the U.S. $3 billion before being scrapped.

Yang, who won a Nobel prize in 1957, believes the money should be used to address social problems, and argues funding the collider will result in lower budgets for other valuable scientific research.

Chances of making any big discoveries are relatively low, Yang said. The CEPC would be used to search for so-called supersymmetry particles, which he says come from “a theory without experimental basis.” Moreover, Yang foresees the collider being run mostly by foreigners and being of little benefit to Chinese scientists. “Among the prominent high-energy physicists in the world, Chinese make up less than 1 or 2 percent,” he wrote.

Wang Yifang, head of the government-run Institute of High Energy Physics (IHEP), the entity behind the collider project, replied on Monday with an article of his own, also published on The Intellectual.

Wang denied that the cost of building CEPC would be endless, adding that international investment would cover 30 percent of the total expenses. He also said that 70 percent of the work would be done by Chinese scientists. Wang believes that building a large collider will attract overseas talent, cultivate young scientists at home, and be a leap for China in high-energy science.

Also in response to Yang’s commentary, Sixth Tone’s sister publication The Paper on Monday published an article based on an interview with Rudiger Voss, head of international relations at CERN in Switzerland.

Voss said that although the Chinese project would allow physicists to study the properties of the Higgs boson with greater precision and accuracy, the experiments would be limited in scope: The energy ranges of such experiments would be confined by the length of the tunnel, which in the case of China’s plans would be circular, and thus fixed.

Plans are currently underway for a new linear collider that would be the result of an international collaborative effort, and would build on the current experiments being carried out at CERN’s LHC. The International Linear Collider project would be extendable in length, allowing for proportional increases in energy levels.

According to media reports, the idea to build a Chinese super collider was first raised in 2012. Financial news outlet Caixin wrote in May that the government had yet to give any official comment.

Additional reporting by Owen Churchill.

(Header image: A view of Compact Muon Solenoid (CMS) Cavern at the European Organization for Nuclear Research (CERN), Meyrin, Switzerland, Feb. 10, 2015. Richard Juilliart/AFP/VCG)