The Physics Briefing Book, a cornerstone document guiding the 2026 Update of the European Strategy for Particle Physics (ESPP), has been released by the Physics Preparatory Group (PPG) and is now available online.

🔗 Read the Physics Briefing Book

Mandated by the CERN Council, the ESPP is Europe’s central decision-making framework for shaping the long-term future of particle physics. Initiated in 2005 and updated in 2013 and 2020, the strategy is built through an extensive consultation process involving CERN’s Member and Associate Member States, as well as international partners.

The 2020 update prioritised the full exploitation of the High-Luminosity LHC and identified an electron–positron Higgs factory as the highest-priority next collider, while also outlining the ambition for a proton–proton collider at the highest achievable energy. It emphasised the importance of broad scientific programmes beyond colliders and the development of roadmaps for R&D in accelerator and detector technologies.

Following significant progress since 2020 — including the completion of the Future Circular Collider (FCC) Feasibility Study and the evolution of the global landscape with major initiatives in the US, China, and Japan — the CERN Council launched a new ESPP update in March 2024. This third update aims to develop a visionary and concrete plan for the next flagship project at CERN, fostering international collaboration and ensuring Europe’s continued leadership in fundamental physics.

The Physics Briefing Book consolidates the scientific input from the global community and summarises discussions from the Open Symposium. It provides the foundation for the European Strategy Group (ESG) as they prepare the final set of strategy recommendations during their five-day meeting at Monte Verità (Ascona, Switzerland) from 1 to 5 December 2025.

This milestone marks a crucial step toward defining the future trajectory of European — and global — particle physics.