The adventure started in 2011. It lead, at the 2020 update of the European Strategy for Particle Physics, to a compelling scientific case for a new electron–positron collider operating as a Higgs factory, followed by further exploration using a proton–proton collider at the highest achievable energy. The successful completion of the FCC Feasibility Study, in Spring 2025, was acknowledged by the particle physics community as a major achievement, leading to a clear message:

The electron–positron Future Circular Collider (FCC-ee)
is recommended as the preferred option
for the next flagship collider at CERN.

[ link to the Recommendations by the European Strategy Group ]

Many questions, from the scientific community at large and the CERN Council in particular, still have to be answered in view of the project approval. Many tools and detailed studies are being developed to prepare the call for detector “Expressions of Interest” that will follow the project approval.

The mandate of the Physics Experiments and Detector (PED) pillar is, with growing participation from the international community, to establish the foundations for the FCC-ee experimental programme through:

• Continuation of the development of detectors R&D and Conceptual Design in view of the international HEP community building and delivering the corresponding reports (CDRs) by 2033.
• Consolidation of machine–detector interface optimisation, background mitigation strategies, and center-of-mass energy calibration, as well as the common computing architecture model and software/analysis framework needed to confirm the experimental uncertainties and expected precision on electroweak variables measurements.
• Forstering and organisation of the theory community effort towards identifying and addressing the corresponding theory challenges.
• Assessment and improvements of the physics case, including in a staged implementation scenario.