Today, we have become used to the CERN family of nations gradually growing, but Poland’s accession to membership in 1991 was a particularly significant moment in the Organization’s history. Poland was the first country from behind the former iron curtain to join, and was soon followed by a range of Eastern European countries throughout the 90s.

When CERN was established under the auspices of UNESCO in the 1950s, countries from East and West were invited to join, but the only eastern country to take up the call was Yugoslavia. As time progressed, that did not prevent fruitful collaboration between the scientific communities of East and West Europe. In the 60s, the Joint Institute of Nuclear Research (JINR) was established near Moscow as a focal point for fundamental research for Eastern European countries, and it was not long before strong ties were established with CERN. For a generation of young physicists, the CERN-JINR summer school became an important rite of passage.

Poland’s involvement with CERN dates right back to the early days, with groups from Warsaw and Krakow forging a strong relationship with the Laboratory. Their contribution to programmes ranging from Bubble Chambers to the properties of strange hadrons and charm production was sufficiently strong that by the time the iron curtain fell, Poland was ready for membership. In the 80s, Polish groups were playing vital roles in established CERN experiments such as the European Muon Collaboration (EMC), as well as new experiments including DELPHI at the Large Electron Positron collider, LEP.

Poland’s accession to CERN had significance beyond the world of particle physics, marking the first step in Poland’s integration into European political structures – it was not until 2004 that Poland became a member of the European Union. Today, Poland’s red and white flag graces the membership rosters of all four major LHC experiments. Polish physicists also play important roles in NA61/SHINE, Compass – the latest successor to EMC – and ISOLDE.

Poland is marking the anniversary with a range of activities, and the CERN Courier takes a detailed look back over 30 years and more of Polish contributions to the Laboratory.