Three physicists, Steven Weinberg, Abdus Salam and Sheldon Glashow, receive the Nobel prize in physics for proposing the electroweak theory. They believe that two of the four fundamental forces – the electromagnetic force and the weak force – are in fact different facets of the same force. Under high-energy conditions such as those in a particle accelerator, the two would merge into the electroweak force. But three hypothetical force-carrier particles described by the theory have yet to be confirmed in experiments: the W+, W- and Z0 bosons. These are heavy particles; so finding them would require an accelerator that could reach an unprecedented level of energy.
The weak side of the force
The search for the W boson