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. There she met Giuseppe, and the pair studied cosmic rays at the Tête Grise laboratory located on the Matterhorn. In 1954 she obtained a fellowship from the International Federation of University Women and joined her future husband at the University of Liverpool developing techniques and experiments for the Synchrocyclotron, CERN’s first accelerator.
In summer 1956 the couple moved to Geneva, joining only a few hundred people at CERN, which had 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 – techniques that she would later adapt to carry out polarisation experiments at the Proton Synchrotron and the Super Proton Synchrotron (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.
In the 1980s Maria participated in the WA78 experiment at the SPS, which was dedicated to the production of bb pairs. She then 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 Maria 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 continued her work at CERN as an honorary member of the personnel. She had a reserved attitude in all circumstances and a deep sense of duty to the community. As Maria explained in an interview in 2012, “every day or every week there is something new connected with our old work”.