The European strategy for particle physics, which is due to be updated by May 2020, will guide the direction of the field to the mid-2020s and beyond. To inform this vital process, the secretariat of the European Strategy Group (ESG) is calling upon the particle-physics community across universities, laboratories and national institutes to submit written input by 18 December 2018.

The update of the European strategy got under way in September when the CERN Council established a strategy secretariat (CERN Courier November 2017 p37). Chaired by Halina Abramowicz, former chair of the European Committee for Future Accelerators (ECFA), the secretariat includes Keith Ellis (chair of CERN’s Scientific Policy Committee), Jorgen D’Hondt (current ECFA chair) and Lenny Rivkin (chair of the European Laboratory Directors group).

The ESG secretariat, which has been assigned the task of organising the update process, proposes to broadly follow the steps of the previous two strategy processes concluded in 2006 and 2013. An open symposium, which in previous editions took place in Orsay (France) and Kraków (Poland), will take place in the second half of May 2019, in which the community will be invited to debate scientific input into the strategy update. With the event expected to attract around 500 participants, the secretariat proposes to hold it over a period of four days.

To prepare for the open symposium, the location of which is expected to be decided by the summer, ESG calls for written contributions towards the end of the year. Input should be submitted via a portal on the strategy-update website, which will be available from the beginning of October once the update has been formally launched by the CERN Council. The link will appear on the CERN Council’s web pages (https://council.web.cern.ch/en) and will be widely communicated closer to the time.

A “briefing book” based on the discussions will then be prepared by a physics preparatory group and submitted to the ESG for consideration during a five-day-long drafting session in the second half of January 2020. A special ECFA session on 14 July 2019 during the European Physical Society conference on high-energy physics in Ghent, Belgium, will provide another important opportunity for the community to feed into the ESG’s drafting session.

Global perspective

The European strategy update takes into account the worldwide particle-physics landscape and developments in related fields, and was initiated to coordinate activities across a large, international and fast-moving community. The third update comes as the scale of particle-physics facilities is leading to increased globalisation of the field and as its research direction evolves.

Understanding the properties of the Higgs boson (which was discovered at CERN just before the previous strategy update) remains a key focus of analysis at the LHC and future colliders, as are precision measurements of other Standard Model (SM) parameters and searches for new physics beyond the SM.

Neutrino physics is another key area of interest, with much experimental activity taking place since the last update. A “physics beyond colliders” programme has also been established by CERN to explore projects complementary to high-energy colliders and projects of national laboratories. The European astroparticle and nuclear-physics communities, meanwhile, recently launched their own strategies (CERN Courier September 2017 p6; March 2018 p7), which will also feed into the ESG update.

“After the discovery of the Higgs boson, the field is presented with a number of challenges and opportunities,” says Abramowicz. “Guided by the input from the community, the European strategy will determine which of these opportunities will be pursued.”