Future Accelerators

Several candidates for future accelerators are discussed. The linear colliders ILC and CLIC will provide electron-positron collision at much higher energy than previously accessible in LEP or SLC. They will explore many details of the Higgs boson and carefully determine its properties. Another candidate for a future accelerator to address the physics of the Higgs boson is the Future Circular Collider (FCC). This large ring will have three times the circumference of LHC. A high-energy muon collider will provide point-like collisions with moderately heavy particles, albeit at the expense of the short lifetime of muons. Many technical details of this approach need to be worked out in the future. Plasma accelerators provide another option to reach high particle energies. They work by exciting plasma waves in a gas and using the emerging electric field to accelerate particles to high energies.