Roland Windmolders, our dear colleague, died suddenly on 27 November 2020 in Prévessin (FR). Of Belgian nationality, he completed his university education at the University of Louvain (BE), first in civil engineering and then in mathematics and physics. At the age of 27, he defended his PhD in particle physics at the University of Louvain, with the highest distinction. At the end of the 1960s, he spent one year at the Lawrence Berkeley National Laboratory (US). He then became an assistant at the Faculty of Science, University of Mons (BE), where he assumed several teaching responsibilities. From 1971 to 1976, his scientific work was connected with the Mirabelle bubble chamber and studies of the kaon–proton and antiproton–proton interactions at a few GeV energy, all within a large international collaboration. This activity meant intense interaction with physics communities across the world, collaboration meetings and conferences. Even before having his PhD, he presented collaborations’ results at international conferences.
In 1975, Roland married Magdeleine. For about 10 years, they lived in Belgium and then moved to Prévessin, to be closer to CERN, as Roland became more and more involved in CERN’s experiments, while still affiliated to the University of Mons. After his official retirement, he continued to be fully active in physics, but was then affiliated to the University of Bonn (DE).
The early 1980s opened a new era in Roland’s physics interests: he joined the European Muon Collaboration (EMC), eventually becoming its longest-serving member. The EMC was a collaboration of over 100 physicists – which was considered large in the 1980s – formed to make experimental studies of the nucleon and nuclei parton structure. Roland brought with him wide experience and knowledge of high-energy interactions, acquired from bubble chamber experiments. He once said with great satisfaction: “In this subject, you can precisely calculate everything.” The EMC made several fundamental discoveries (e.g. the “EMC effect” and the proton spin “puzzle”). Roland continued to work on muon physics within the New Muon Collaboration, the Spin Muon Collaboration and then COMPASS, which is still running. He continued to work with COMPASS until his retirement in 2018.
Roland was a true scientist and a great collaborator: his contribution to deep inelastic physics experiments cannot be overstated. His profound and mature understanding of all details of deep inelastic scattering (DIS) experiments and data analysis consistently made him a leader in finding new solutions to physics problems. He would always come up with new ideas, which would develop into many-year-long experimental studies. Calm, friendly and shy, Roland attracted discussions and debates at all moments; coffee breaks were particularly fruitful. He never applied for or agreed to take on any high-level positions; his leading role in physics was, in spite of that, never questioned. His style was to work quietly in the background without fuss. However, he was always at the forefront when furthering the collaboration’s interests and understanding the physics.
Roland was a thorough gentleman who got things done. He was always willing to help and to advise others, and his help was often sought. He was a true “enlightenment” man: cultivated and sophisticated in arts, literature and history, which he systematically explored during his many travels. Gifted with a wonderful memory, he guided his colleagues with fantastic, detailed and cultural advice. In particular, he had an intimate knowledge of CERN’s surrounding region, which he was always willing to share with his colleagues to help them appreciate the beauties of the region. He will be dearly missed.
His colleagues and friends