(Image: CERN)
Geneva, 11 October 2024. During its two hundred-and-eighteenth session, the CERN Council formally finalised the organisation of the European Strategy process by appointing the Physics Preparatory Group, whose aim will be to prepare the scientific contribution based on the input from the community. The European Strategy is driven by the CERN Council, the highest authority of the Organization, composed of representatives of all Member States. During the next year and a half, the whole community will work to develop a common vision for the future of particle physics in Europe - including which major project should succeed the Large Hadron Collider at CERN. The process is expected to be concluded at the end of 2025, after which the European Strategy Group will submit its recommendations to the Council.
Particle physics, the study of the smallest constituents of matter and the laws of nature at the most fundamental level, is at a fascinating juncture. The discovery of the Higgs boson at CERN's Large Hadron Collider (LHC) in 2012 confirmed the final predicted piece of the Standard Model of particle physics - a powerful quantum theory which describes three of nature's four fundamental forces. Yet, despite its unparalleled success, the Standard Model explains only 5% of the Universe and is not able to answer other outstanding questions. It cannot account for the invisible "dark matter" that influences the motion of galaxies, nor what is causing the expansion of the Universe to speed up. It also falls short in explaining why matter and antimatter did not annihilate each other in the first moments of the Big Bang to leave a featureless sea of radiation. Studying the Higgs boson and other elementary particles in greater detail and exploring nature at higher energies using next-generation colliders will be key in tackling these and other profound open questions.
"The discoveries at the LHC of the Higgs particle and more than 70 new composite hadrons have been highlights of an amazing decade in particle physics dominated by experiments at CERN, which will be continued at the LHC and its high-luminosity upgrade until 2041. Researchers across the globe agree that deeper study of the Higgs particle is certain to lead to very valuable scientific results, and the CERN Council is united in its vision to have CERN continue to provide the most exciting experimental scientific programme in high energy physics with the aid of the best possible technology. The community and the Council therefore eagerly await the recommendations of the European Strategy Group on the best path to be taken", said CERN Council President, Eliezer Rabinovici, Hebrew University of Jerusalem.
The third update of the European Strategy for Particle Physics was launched by the CERN Council on 21 March. In June, the Council elected Professor Karl Jakobs (University of Freiburg) as Strategy Secretary and established the European Strategy Group, which will be responsible for submitting final recommendations to the Council for approval in early 2026. The European Strategy Group remit states that the aim of the Strategy is to develop "a visionary and concrete plan that greatly advances human knowledge in fundamental physics through the realisation of the next flagship project at CERN".
The previous update of the European Strategy for Particle Physics, completed in 2020, recommended that Europe, together with its international partners, should investigate 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.
Since then significant progress has been made and an international consensus reached on the scientific case for a Higgs factory. A mid-term report on the feasibility study for the proposed multi-stage Future Circular Collider (FCC) at CERN was presented in March 2024, with a final report expected in spring 2025. In December 2023, a rigorous planning exercise in the US prioritised support for a Higgs factory based outside the US. It was followed in April 2024 by a joint statement of intent by CERN and the US government to continue collaboration on the feasibility study for the FCC Higgs factory (FCC-ee) and on its construction and physics exploitation, should the CERN Member States determine the FCC-ee to be CERN's next world-leading research facility.
"Given the long timescales involved in building large colliders, it is vital that the community is united so as to enable the Council to take a decision on the next collider at CERN in 2027/2028. There is excellent progress with the LHC and no new indication that would change our physics priorities: understanding the Higgs boson much better and exploring further the energy frontier are key to the next project", said Strategy Secretary, Karl Jakobs, University of Freiburg.
In addition to identifying the preferred option for the next collider at CERN, the Strategy update is expected to prioritise alternative options to be pursued if the chosen preferred plan turns out not to be feasible or competitive. It will also indicate areas of priority for scientific exploration complementary to colliders, as well as for other items identified as relevant to the field. These include accelerator, detector and computing research and development, theory developments, actions to minimise environmental impact and improve the sustainability of accelerator-based particle physics, initiatives to attract, train and retain early-career researchers, and public engagement.
During its September session the Council appointed members of the Physics Preparatory Group, which will prepare scientific input to the work of the European Strategy Group based on the views it gathers from the community. The Council also announced that the Strategy Open Symposium, at which researchers will be invited to debate the future orientation of European particle physics, will take place in Venice from 23 to 27 June 2025.
"This year we celebrate seven decades of groundbreaking progress in fundamental science and technology at CERN, achieved through international collaboration. This success is the result of CERN's unique culture and the CERN community's boldness in pursuing projects at the limit of human capabilities and has only been possible thanks to the support of our Member and Associate Member States and our partners from all over the world. Future projects will be even more challenging, but their expected physics and technological impact is immense. The future of CERN and the field is bright", said CERN Director-General, Fabiola Gianotti.
