Mark Rayner (1983 – 2026)

It was with profound shock and sadness that we learned of the sudden passing of staff member Mark Rayner, Editor of CERN Courier magazine, on 23 March.

Mark was born in Hounslow, England, on 7 October 1983 and studied physics at Worcester College, University of Oxford, from 2002 to 2006. His journey in particle physics began in 2005, when he spent three months at CERN as a Summer Student working on tests of the ATLAS transition-radiation-tracker end caps. He continued at Oxford with a PhD, participating in the Muon Ionisation Cooling Experiment (MICE) based at the Rutherford Appleton Laboratory. His thesis described the development of a novel technique for characterising the MICE muon beam and demonstrating its suitability for a muon cooling measurement, an essential step on the path towards a possible neutrino factory and muon collider. In 2011, Mark moved from accelerator physics to neutrino physics, joining the University of Geneva both as a lecturer and as a researcher working on the T2K, Hyper-Kamiokande and BabyMIND experiments, to which he contributed with data analysis and detector development.

A passionate educator and communicator, Mark trained as an apprentice physics teacher at Ecole Internationale de Genève in 2018. The following year he joined CERN as a senior fellow working on the CERN Courier magazine, disseminating the latest developments in global high-energy physics. He played a major role in the launch of the CERN Courier website and rose quickly to become the magazine's deputy editor. When his fellowship ended, Mark moved to the World Economic Forum, where he managed the production of a portfolio of publications and tools relating to education, skills and learning and served as lead author for the Future of Jobs report 2023.

Mark returned to CERN as a staff member in 2024, and as Editor of the CERN Courier. Over a short period, his talent for language and his creativity in graphics and data journalism raised the bar for CERN's flagship publication. He also paid particular attention to improving the visibility of gender diversity in the Courier and to developing the magazine's online presence, enabling him to connect particle physics with new audiences. He took great pride in his work and in engaging with authors to shape their stories, and was widely recognised for his dignity and professionalism both among his colleagues and members of the international particle-physics community.

Above all, Mark cared deeply about everything he did, and especially about the well-being of others. His pursuit of excellence and his remarkable attention to detail set a standard that inspired those around him, and this is reflected in the deeply motivated team that he built and nurtured. He was highly cultured and sang in the Geneva Gospel Choir.

Mark was a man of great warmth and spirit and of quiet generosity, whose presence brought light to those fortunate enough to know him. He will be remembered with great respect and will be profoundly missed.

His friends and colleagues

A memorial celebrating Mark's life will take place on Friday 17 April from 15:45-16:45 at Chapelle Camoletti, Cimetière de Saint-Georges, 1213 Petit-Lancy, Geneva.