European Particle Physics Strategy: Community Contributions Collected

Logo for the 2026 update of the European Strategy for Particle Physics (image: CERN)

The submission period for community input to the 2026 update of the European Strategy for Particle Physics (ESPP) has officially closed, with a total of 263 contributions received. These submissions span the entire field of high-energy physics and reflect priorities from individual researchers to national institutions. Expert panels will now begin reviewing the input in preparation for a community-wide Open Symposium, scheduled to take place in Venice from 23 to 27 June.

“We’re encouraged by the breadth and depth of the contributions, especially the national perspectives and proposals for CERN’s next major accelerator initiative,” said Karl Jakobs, Strategy Secretary and professor at the University of Freiburg. “The European Strategy Group and the Physics Preparatory Group now face the important task of synthesizing this input ahead of the Open Symposium, aiming to reach a collective vision for the field’s future by year-end.”

The ESPP is revised every 5 to 7 years under the direction of the CERN Council, which includes representatives from CERN’s Member and Associate Member States. Initiated in March 2024, the current update—organized by the Council-appointed European Strategy Group—seeks to define a bold and actionable roadmap for advancing our understanding of fundamental physics, including the development of CERN’s next flagship project.

A significant number of submissions emphasize the critical role of the Higgs boson in deepening our grasp of the Universe, advocating for further investigation into its properties. Other widely supported topics include the search for elusive dark matter and continued exploration of neutrinos.

The community’s ambitions in particle physics are supported by advancements in accelerator technology, detector systems, and computing. These areas are critical for enabling the next major research program, as emphasized by the 2020 Strategy, which called for dedicated roadmaps for research and development.

Contributions related to these technologies—as well as six key particle physics subfields—will be evaluated by the Physics Preparatory Group (PPG), a panel of subject-matter experts. Each proposed project will be assessed based on its scientific promise, measured against clearly defined physics benchmarks.

A common theme in submissions for major projects and experiments is sustainability, reflecting CERN and its scientific community’s strong commitment to environmental responsibility.

A significant portion of the input also focuses on proposals for a successor to the Large Hadron Collider (LHC), which is set to conclude operations in 2041. This aligns with the recommendations of the 2020 Strategy update. The current review will also consider alternative strategies should the preferred project prove unfeasible or less competitive.

“The discovery of the Higgs boson at the LHC in 2012 unlocked a new path to addressing some of the most profound questions in physics, and colliders remain the only tools capable of producing and analyzing this unique particle,” noted Costas Fountas, President of the CERN Council. “Choosing an appropriate follow-up to the LHC is crucial for preserving CERN’s leadership in the field, and the Council eagerly anticipates the forthcoming recommendations from the ESPP process.”

Multiple submissions highlight potential future collider projects at CERN. The feasibility study for the Future Circular Collider (FCC), recommended in the 2020 Strategy update, has now been completed, with the final report released on March 31. The FCC envisions a 91-kilometer circular accelerator that would initially operate as a high-precision electron-positron collider—serving as a “Higgs and electroweak factory”—and later evolve into a high-energy hadron collider.

Another proposal put forward is a Linear Collider Facility at CERN, which could incorporate technologies from the International Linear Collider (ILC), the Compact Linear Collider (CLIC), or other advanced systems. Additional concepts include a muon collider, as well as the LEP3 and LHeC projects, the latter two leveraging the existing LHC tunnel. However, implementing the LHeC would require the construction of an additional energy-recovery linear accelerator.

Over 50 submissions were received from national governments and research laboratories, including several from outside Europe. Reflecting the ESPP's mandate, many of these contributions clearly state preferences regarding which major project should succeed the LHC. The European Strategy Group (ESG) will weigh scientific potential alongside other critical considerations during its evaluation.

“To thoroughly assess the wide range of proposals and compare large-scale initiatives, it’s essential to factor in national perspectives, project timelines, costs, environmental sustainability, and other criteria,” said Karl Jakobs. “We’ve organized the review process into seven dedicated working groups, which—together with input from the Physics Preparatory Group and the results of the Open Symposium—will guide the final discussions during the Strategy Drafting Session in December. The 2026 ESPP update process is in full swing, and we look forward to continued robust participation from the broader community, particularly during the Open Symposium.”