Future Large Circular Colliders

by Paolo Giacomelli (INFN Bologna)

Tuesday 14 May 2024, 16:00 → 18:00 Europe/Berlin

A.1.01/03 - Alps (New)

The last European Strategy update defined a Higgs factory as the highest priority for the future of particle physics. A Higgs factory could be realised with a large leptonic circular collider or a large electron-positron linear collider. I will show that the best choice is that of a circular collider, which can provide much higher luminosities and can explore the whole range of electroweak physics, being therefore much more than just a Higgs factory.

There are two such projects in the world, the Future Circular Collider, FCC, being proposed at Cern, and the Circular Electron Positron Collider (CEPC), proposed to be located in a newly built laboratory in China. These colliders would be about 100 km in circumference and capable of producing e⁺e^- collisions ranging in center-of-mass energy from the Z⁰ peak all the way to just above the ttbar threshold. Both infrastructures would operate in two phases, the first one colliding electrons and positrons (FCC-ee and CEPC) and then in a second phase installing a proton-proton collider (FCC-hh and SPPC) reaching center-of-mass energies above 100 TeV. This is another compelling reason why a circular collider is preferrable to a linear collider.

I will highlight some of the physics motivations of a large circular collider and then describe in some detail the two collider proposals. I will then also focus on one possible detector concept, suitable for both FCC-ee and CEPC, called Innovative Detector for E⁺e^- Accelerator (IDEA).

I will also discuss why a combination of a large leptonic collider followed by a proton-proton collider provides the best possible infrastructure for particle physics for the next 60-70 years.