Forward-looking: The European Organization for Nuclear Research, also known as CERN, is an international research laboratory operating the world's largest particle accelerator. The Large Hadron Collider (LHC) played a crucial role in confirming the discovery of the Higgs boson. However, CERN now aims to delve deeper into the exploration of new phenomena in physics.
CERN is in the process of conducting a midterm review for the feasibility study of the Future Circular Collider (FCC), the next-generation particle accelerator unveiled in 2020. According to CERN's announcement, the construction of the FCC is estimated to cost €20 billion ($21.5 billion), and the proposed machine would boast a 91 km circumference, enabling the collision of subatomic particles at a maximum energy of 100 teraelectronvolts (TeV).
Members of CERN are currently engaged in discussions regarding the construction plans for the FCC, a machine described by scientist Tara Shears (a member of the LHCb experiment at the Large Hadron Collider) as larger, faster, and more powerful than the LHC. If approved, CERN Director Fabiola Gianotti stated that the new particle accelerator would serve as the "most powerful microscope" ever built, facilitating the study of natural laws at the smallest scales and highest energy levels.
CERN aims to secure approval for the FCC building plans within the next five years, with the anticipation of commencing the first experiments in the 2040s, following the completion of the LHC's runs. Shears mentioned that CERN scientists are currently conducting a study to assess the feasibility of the accelerator, with the findings expected by 2025. The final decision regarding the construction phase of the FCC could be reached by 2028.
The FCC is anticipated to shed new light on the nature of dark matter, dark energy, and other mysterious phenomena, potentially leading to breakthrough scientific discoveries in particle physics research. Shears noted that the new particle accelerator could unveil previously unknown features of the Higgs boson and Higgs field, which are beyond the study capabilities of the LHC at its energy levels of 14 TeV.
However, the proposal for a larger particle collider has faced criticism from David King, the former government chief scientific adviser in the UK, who labeled the FCC as a "reckless" idea at a time when the world is already grappling with extreme environmental threats. Sabine Hossenfelder, a researcher at the Munich Center for Mathematical Philosophy, expressed skepticism, stating that there is no evidence that the FCC would necessarily reveal new insights into particle physics and the Standard Model.
According to Hossenfelder, the 91 km machine would likely offer improved measurements of some constants already known within the Standard Model, but it might not contribute significantly to human knowledge and scientific research, contrasting with the impact of the LHC. She suggests that particle physicists need to acknowledge that their era might be concluding, with quantum physics emerging as the next major frontier in science, where the FCC may not play a pivotal role.