European Strategy for Particle Physics

The European Strategy for Particle Physics has guided the direction of the field for the past two decades. The most recent update, completed in June 2020, prioritised the full exploitation of the LHC, detector upgrade projects for the high-luminosity phase of the LHC, investigation of the technical and financial feasibility of a future hadron collider at CERN with a centre-of-mass energy of at least 100 TeV and with an electron-positron Higgs and electroweak factory as a possible first stage,  and the continued development of scientific programmes beyond colliders at CERN as well as in other laboratories in Europe and worldwide. The Strategy also called for roadmaps to be drawn up setting the course of research and development (R&D) in the fields of particle accelerator and detector technology for the coming years.

Since the last update, excellent progress has been made at CERN and beyond in preparation for future colliders. A Feasibility Study for the realisation of the Future Circular Collider (FCC) was launched by the CERN Council following the adoption of the 2020 Strategy Update and a mid-term report was presented in February 2024. A final report is expected to become available in 2025. In addition, the international landscape for future colliders has also become clearer: in December 2023 the P5 prioritisation process concluded in the USA and a Technical Design Report for the CEPC project in China was released. The ILC project has established an International Technology Network. Finally, the recommended roadmaps have been duly established, one in the field of accelerator R&D and in the field of detector R&D.

Given the long timescales involved in building new large-scale facilities and the importance of long-term community engagement, the next update of the European Strategy process is timely.

According to its remit, the Strategy should aim to develop a visionary and concrete plan that greatly advances knowledge in fundamental physics through the realisation of the next flagship project at CERN. This plan should attract and value international collaboration and allow Europe to continue to play a leading role in the field.

Regarding a future collider project, the Strategy update should include the preferred option for the next collider at CERN and prioritised alternative options to be pursued if the preferred plan turns out not to be feasible or competitive.