Golden Jubilee photos: The Search for the Bosons
On 25 January 1983, this historic press conference announced the observation of W particles in the UA1 experiment at CERN, and was followed by another in May when Z particles had been found.
Natural phenomena at this scale are described by four forces, gravity, electromagnetism and the strong and weak nuclear forces. But in 1968 a new theory predicted that electromagnetism and the weak nuclear force were manifestations of a single 'electroweak' interaction, proposing that it would be communicated by the charged W+ and W- bosons and the neutral Z0 boson. In 1979 Sheldon Glashow, Abdus Salam and Steven Weinberg won the Nobel Prize for Physics for this work.
Finding the bosons predicted by the theory involved a huge effort. CERN had to develop new technology and engineering. Innovations included making crucial advances in techniques for producing, gathering and controlling antimatter (see Bulletin 26/2004), converting the SPS into a proton-antiproton collider, and building two new detectors, the 2000 ton UA1 and the 200 ton UA2.
In recognition of these efforts, the two most instrumental collaborators in the discoveries, Carlo Rubbia, head of the UA1 project, and Simon van der Meer, inventor of the stochastic cooling technique, were awarded the Nobel Prize for Physics, 1984.
