Alison Wright

The 1965 Nobel Prize in Physics was shared by Sin-Itiro Tomonaga, Julian Schwinger and Richard Feynman “for their fundamental work in quantum electrodynamics, with deep-ploughing consequences for the physics of elementary particles”. The three physicists had, independently, created a solid relativistic theory of quantum electrodynamics (QED). Each had conquered the problem in their own style — and the diversity of those styles is apparent in their lectures prepared for the Nobel ceremony.

For particle physicists in Europe and the USA, it was the most eagerly anticipated result of 2024. In September, the CMS Collaboration — working with one of the two large, general-purpose detectors at CERN’s Large Hadron Collider — finally announced their first measurement of the mass of the W boson: 80,360.2 ± 9.9 MeV.

Suddenly there were particles everywhere. After a slow start from the late 1800s (first the electron, the proton, then later the neutron, the positron), by the early 1960s a whole host of particles had been discovered: the muon, pions, kaons; the antiproton; lambda, omega and xi baryons. Three forces were in play — electromagnetic, weak and strong — but experiments were streaking far ahead of a theory that could explain their results.