Hyper-CP experiment. Physicist Casey Durandet working on the Hyper-CP experiment at Fermilab, the particle physics laboratory near Chicago, USA. She is using scintillating fibres (yellow) as part of the detection system of the apparatus. Hyper-CP aims to study charge parity (CP) violation, one of the main research topics of particle physics at the beginning of the 21st century. Hyper-CP compares the decay properties of hyperons (subatomic particles composed of three quarks, at least one of which is a strange quark) and their antiparticles. Differences in these decay properties could help explain the evolution of matter in the Universe. Photographed in 1996.