Overview
- CERN powered off the Large Hadron Collider on June 29, 2026 to start Long Shutdown 3, a planned four-year engineering programme to convert the machine into the High‑Luminosity LHC.
- Engineers have begun replacing key hardware including superconducting dipole magnets, installing radiofrequency “crab cavities” for better beam overlap, and rebuilding detector and trigger systems to handle much denser collision environments.
- The upgrade aims to raise per‑second collision rates by roughly five to seven times and to collect about ten times more data over the HL‑LHC run, increasing the chance of observing rare processes.
- Physicists will use the larger datasets to measure the Higgs boson with far greater precision and to expand searches for dark matter candidates, sources of the matter–antimatter imbalance, and other phenomena that lie beyond the Standard Model.
- Work will continue in laboratories while the tunnel is offline and the project targets a phased restart and commissioning around June 2030 with ongoing data analysis by thousands of researchers during the shutdown.