CERN wants to build a next-generation particle accelerator that could cost up to €20 billion.

The proposed Future Circular Collider (FCC) in Switzerland and France would have a circumference of over 90 kilometers and collide protons at energies of 100 teraelectronvolts (TeV), compared to the 14 TeV achieved by the lab's Large Hadron Collider (LHC). In a report to CERN's council, made up of representatives from the organization's 23 member states, officials detailed the FCC proposal, and sought approval for work to begin on the accelerator in the next five years.

Scientists supporting this ambitious project want to start building sooner rather than later so the FCC is ready to start operating when the LHC ends its experimental runs in the 2040s.

"The FCC will not only be a wonderful instrument to improve our understanding of fundamental laws of physics and of nature," CERN director general Fabiola Gianotti said during a Monday briefing. "It will also be a driver of innovation," she added, according to The Financial Times.

Not everyone is onboard with Gianotti's vision, however. Some experts believe the €20 billion (£17.1 billion, $21.5 billion) price tag does not represent value for money and that the funds could be spent more wisely on research that addresses diseases or climate change. Sir David King, a chemist and a former chief scientific advisor for the British government, called the project "reckless" in an interview.

"When the world is faced with threats from the climate emergency, would it not be wiser to channel these research funds into the endeavors to create a manageable future?" he asked the BBC.

Others reckon the FCC is risky because it might not lead to any new breakthroughs. The LHC is best known for confirming theories that predicted the existence of the Higgs boson, a fundamental particle proposed in 1964 by a team of physicists. They came up with the idea of the Higgs field - a fundamental field that permeates all of space, and gives particles mass.

Scientists have performed further experiments following the confirmation of the Higgs boson in 2012, but haven't since achieved anything to compare with that finding, leading some to question whether it's worth plowing more resources into CERN.

Gianotti, however, believes new physics discoveries will only be revealed if subatomic particles are smashed together at higher speeds, which requires a larger and more powerful accelerator. Data collected from future experiments could map the properties of the Higgs boson to study how particles like electrons, muons, and quarks gained mass shortly after the Big Bang.

Learning more about dark matter is another hoped-for outcome. The FCC could rule out whether dark matter comes from a class of particles known as WIMPs (weakly interacting massive particles), according to physicists who support the €20B project. ®

https://www.theregister.com//2024/02/06/cern_dark_matter_accelerator_proposal/