We are deeply saddened to learn that Maria Fidecaro, an experimental physicist who joined CERN in 1957, passed away on 17 September. Maria was a familiar face to the CERN community until long into her retirement, often seen arm-in-arm with her husband Giuseppe as they made their way through the CERN corridors. She was also well-known to CERN visitors, featuring prominently in the Synchrocyclotron exhibition’s film.
Born in Rome in 1930, Maria completed her university studies at La Sapienza in 1951, studying cosmic rays using a detector located on the Matterhorn. In 1954, she and her future husband went to the University of Liverpool. Maria had obtained a fellowship from the International Federation of University Women while Giuseppe had obtained a CERN fellowship to carry out research at the Synchrocyclotron, CERN’s first accelerator. After their marriage in July 1955, they carried out pion experiments: Maria with a diffusion chamber and Giuseppe with a lead-glass Cherenkov counter.
In summer 1956, the couple moved to Geneva, joining only a few hundred people at CERN, the Laboratory having been established just two years earlier. Maria obtained a CERN fellowship in 1957 and began working in a team of three that was developing a novel method to provide polarised proton beams at the Synchrocyclotron and would later carry out polarisation experiments at the PS and SPS. She remained at CERN for the rest of her career, where her early research interests included charge-exchange nucleon–nucleon scattering and proton–proton elastic scattering.
During the 1990s, Maria worked on detectors and analysis for the CPLEAR experiment, which was designed to enable precision measurements of CP, T and CPT violation in the neutral kaon system. She designed and led the construction of a high-granularity electromagnetic calorimeter, helping CPLEAR to achieve new levels of precision in the study of fundamental symmetries. From 1991 to 1995, she was group leader of the CPL group in the Particle Physics Experiments division. She also took part in the NA48/2 experiment, searching for CP violation in the decay of charged kaons, and contributed to the early phases of NA62.
Maria celebrated her retirement in 1995, but this did not mean the end of her research. She and Giuseppe continued their work at CERN as honorary members of the personnel. As Maria explained in an interview in 2012, “every day or every week there is something new connected with our old work”.
A funeral service will be held at the Italian Catholic Mission of Geneva on Friday 22 September at 2.30 p.m.
A full obituary article will appear in the CERN Courier.