PATRICE LOIEZ, CERN / SCIENCE PHOTO LIBRARY PATRICE LOIEZ, CERN / SCIENCE PHOTO LIBRARY
Editorial use only. This image may not be used to state or imply endorsement by CERN of any product, activity or service.
Discovery of the Z particle, one of the carriers (gauge particles) of the weak nuclear force. This photographically coloured version of the original electronic image obtained from the UA1 detector at CERN, Geneva, on April 30, 1983, shows the tracks of an electron-positron pair (coloured purple) emerging back-to-back from the point where a proton and an antiproton collided at high energy in CERN's Super-Proton-Synchrotron (SPS) accelerator. The collision also produced a debris of other particles whose tracks are visible. The Z particle itself lives too briefly to be seen, but its existence is deduced from the tell-tale "signature" of the electron-positron pair.
Model release not required. Property release not required.