1983: discovery of the W and Z particles

In 1979, CERN took the bold decision to convert the Super Proton Synchrotron (SPS) into a proton–antiproton collider. The invention of a technique called stochastic cooling, which would allow sufficient numbers of antiprotons to be accumulated to make a beam, was the key to the success of this project.

The first proton–antiproton collisions were achieved just two years after the project was approved, and two experiments, named UA1 and UA2, started to search the collision debris for signs of W and Z particles, carriers of the weak interaction between particles.

In 1983, CERN announced the discovery of the W and Z particles. The discovery was so important that Carlo Rubbia and Simon van der Meer, the two key scientists behind the discovery, received the Nobel Prize in physics only a year after. Carlo Rubbia was instigator of the conversion of the SPS accelerator into a proton-antiproton collider and was spokesperson of the UA1 experiment. Simon van der Meer invented the stochastic cooling technique vital to the collider’s operation.