The European Strategy for Particle Physics (ESPP), mandated by the CERN Council, takes place on average every six years and defines the long-term future of the field. It is developed through broad consultation with the particle physics community. The 2026 ESPP update aims to identify CERN’s next flagship project to succeed the LHC/HL-LHC.
Updating the ESPP requires months of work from the scientific community and from dedicated bodies: the European Strategy Group (ESG) and the Physics Preparatory Group (PPG). The final outcome of this process is a document presenting the studies carried out and the recommendations made. Before the finalization of this document, an important moment of sharing and discussion takes place: the Open Symposium of the scientific community.
For this update of the European Strategy for Particle Physics, the Open Symposium was held at the Lido of Venice from 23 to 27 June 2025.
More than 625 scientists from all over the world attended in person. The Symposium had an even wider audience since the presentations were streamed live and remain available online (YouTube videos) along with the presentation slides.
Contributions from the particle physics community were accepted until 26 May. They were reviewed by the ESG and distributed among the PPG working groups, which produced syntheses. The Open Symposium was structured around the work of the PPG and ESG based on these contributions.
On 23 June, after a plenary session opening the symposium, parallel three-hour sessions were held in which the PPG working groups gave detailed technical presentations on:
- electroweak physics
- accelerator technology,,
- neutrinos and cosmic messengers,
- strong interaction,
- flavour physics,
- detector technology,
- physics beyond the Standard Model,
- dark matter and the dark sector,
- scientific computing.
On 24 June, the day began with presentations of major future accelerator projects (FCCee, FCChh, a linear collider for CERN, LEP3, LHeC, muon collider, visions for a linear collider at CERN, in China, Japan, and the US).
- Overarching topics part 1
- Overarching topics part II and closeout
- Large-scale accelerator projects part 1
- Large-scale accelerator projects part 2
From 24 to 26 June, the agenda was built around plenary presentations from each PPG working group, followed by 45 minutes of discussion with the audience.
On 27 June, the closing of the symposium was led by the ESG and its own working groups, covering : analysis of national contributions, the role of national laboratories, relations with other fields of physics, communication, early careers, sustainable development, technology and knowledge transfer, and attempts to compare the large projects. The final presentation, “Key Messages from the Symposium,” was given by Karl Jakobs, Secretary of the ESG.
The conclusion was that the FCC-ee/hh program enjoys massive support, with no major technical barriers identified. A clear roadmap, sustained R&D, and the preservation of a diverse scientific program are deemed essential to maintain Europe’s leadership in particle physics for the coming decades.
The presentations and discussions held during the Symposium were rich and will enable the scientific community to refine or add further contributions until 14 November 2025.